feat: Source generated Serialization/Deserialization (#550)

### Features
* Fully abstracts serialization by using compile-time attributes.
* Supports serializing the following:
  - Primitives (integers, strings, etc)
  - IP Addresses
  - BigDecimal
  - DateTime, Delta DateTimes
  - TimeSpan
  - Server.Race
  - Server.Map
  - Point2D, Point3D, Rect2D, Rect3D
  - Existing/New `ISerializable` references
  - Lists/Sets of serializable types
  - Type with a `Serialize` method and constructor that takes an `IGenericReader`
* Supports forward-only migration
* Supports existing RunUO deserialization for older versions by changing to the following signature:
  - `public void OldDeserialize(IGenericReader reader, int version)`
  - Must remove deserializing the version since this is already done
* Supports serializing from private fields or custom made properties.
* Types do not require inheriting Item/Mobile. Code gen will fully create `ISerializable` information.
  - This is not recommended yet, since it requires wiring to `Persistence` which will cause lots of unresolved symbol errors until code gen is built.

### Example
```cs
using System.Collections.Generic;

namespace Server.Items
{
    [Serializable(1)]
    public partial class TestItem1 : Item
    {
        [SerializableField(1)]
        [SerializableFieldAttr("[CommandProperty(AccessLevel.Administrator)]")]
        private List<Item> _someProperty;

        private void Deserialize(IGenericReader reader, int version)
        {
        }
    }
}
```

Generates this:
```cs
namespace Server.Items
{
    public partial class TestItem1
    {
#pragma warning disable 0414
        private const int _version = 1;
#pragma warning restore 0414

        [CommandProperty(AccessLevel.Administrator)]
        public System.Collections.Generic.List<Server.Item> SomeProperty
        {
            get => _someProperty;
            set
            {
                if (value != _someProperty)
                {
                    ((ISerializable)this).MarkDirty();
                    _someProperty = value;
                }
            }
        }

        public TestItem1(Serial serial) : base(serial)
        {
        }

        public override void Serialize(IGenericWriter writer)
        {
            var savePosition = ((Server.ISerializable)this).SavePosition;
            if (savePosition > -1)
            {
                writer.Seek(savePosition, System.IO.SeekOrigin.Begin);
                return;
            }
            writer.WriteEncodedInt(_version);
            writer.Write(_someProperty);
        }

        public override void Deserialize(IGenericReader reader)
        {
            var version = reader.ReadEncodedInt();
            if (version < 1)
            {
                OldDeserialize(reader, version);
                ((Server.ISerializable)this).MarkDirty();
                return;
            }
            SomeProperty = reader.ReadEntityList<Server.Item>();
        }
    }
}
```

And this:
```json
{
  "version": 1,
  "type": "TestItem1",
  "properties": [
    {
      "name": "SomeProperty",
      "type": "System.Collections.Generic.List\u003CServer.Item\u003E",
      "rule": "ListMigrationRule",
      "ruleArguments": [
        "Server.Item",
        "SerializableInterfaceMigrationRule"
      ]
    }
  ]
}
```

Projects/SerializationGenerator/SerializableMigration/Rules/ListMigrationRule.cs

@@ -0,0 +1,133 @@
+/*************************************************************************
+ * ModernUO                                                              *
+ * Copyright 2019-2021 - ModernUO Development Team                       *
+ * Email: hi@modernuo.com                                                *
+ * File: ListMigrationRule.cs                                            *
+ *                                                                       *
+ * This program is free software: you can redistribute it and/or modify  *
+ * it under the terms of the GNU General Public License as published by  *
+ * the Free Software Foundation, either version 3 of the License, or     *
+ * (at your option) any later version.                                   *
+ *                                                                       *
+ * You should have received a copy of the GNU General Public License     *
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>. *
+ *************************************************************************/
+
+using System;
+using System.Collections.Immutable;
+using System.Text;
+using Microsoft.CodeAnalysis;
+
+namespace SerializationGenerator
+{
+    public class ListMigrationRule : ISerializableMigrationRule
+    {
+        public string RuleName => nameof(ListMigrationRule);
+
+        public bool GenerateRuleState(
+            Compilation compilation,
+            ISymbol symbol,
+            ImmutableArray<AttributeData> attributes,
+            ImmutableArray<INamedTypeSymbol> serializableTypes,
+            out string[] ruleArguments
+        )
+        {
+            if (symbol is not INamedTypeSymbol namedTypeSymbol || !symbol.IsList(compilation))
+            {
+                ruleArguments = null;
+                return false;
+            }
+
+            var listTypeSymbol = namedTypeSymbol.TypeArguments[0];
+
+            var serializableListType = SerializableMigrationRulesEngine.GenerateSerializableProperty(
+                compilation,
+                "ListEntry",
+                listTypeSymbol,
+                attributes,
+                serializableTypes
+            );
+
+            var length = serializableListType.RuleArguments.Length;
+            ruleArguments = new string[length + 2];
+            ruleArguments[0] = listTypeSymbol.ToDisplayString();
+            ruleArguments[1] = serializableListType.Rule;
+            Array.Copy(serializableListType.RuleArguments, 0, ruleArguments, 2, length);
+
+            return true;
+        }
+
+        public void GenerateDeserializationMethod(StringBuilder source, string indent, SerializableProperty property)
+        {
+            const string expectedRule = nameof(ListMigrationRule);
+            var ruleName = property.Rule;
+            if (expectedRule != ruleName)
+            {
+                throw new ArgumentException($"Invalid rule applied to property {ruleName}. Expecting {expectedRule}, but received {ruleName}.");
+            }
+
+            var ruleArguments = property.RuleArguments;
+            var listElementRule = SerializableMigrationRulesEngine.Rules[ruleArguments[1]];
+            var listElementRuleArguments = new string[ruleArguments.Length - 2];
+            Array.Copy(ruleArguments, 2, listElementRuleArguments, 0, ruleArguments.Length - 2);
+
+            var propertyName = property.Name;
+            var propertyVarPrefix = $"{char.ToLower(propertyName[0])}{propertyName.Substring(1, propertyName.Length - 1)}";
+            var propertyIndex = $"{propertyVarPrefix}Index";
+            var propertyEntry = $"{propertyVarPrefix}Entry";
+            var propertyCount = $"{propertyVarPrefix}Count";
+
+            source.AppendLine($"{indent}{ruleArguments[0]} {propertyEntry};");
+            source.AppendLine($"{indent}var {propertyCount} = reader.ReadEncodedInt();");
+            source.AppendLine($"{indent}{propertyName} = new System.Collections.Generic.List<{ruleArguments[0]}>({propertyCount});");
+            source.AppendLine($"{indent}for (var {propertyIndex} = 0; {propertyIndex} < {propertyCount}; {propertyIndex}++)");
+            source.AppendLine($"{indent}{{");
+
+            var serializableListElement = new SerializableProperty
+            {
+                Name = propertyEntry,
+                Type = ruleArguments[0],
+                Rule = listElementRule.RuleName,
+                RuleArguments = listElementRuleArguments
+            };
+
+            listElementRule.GenerateDeserializationMethod(source, $"{indent}    ", serializableListElement);
+            source.AppendLine($"{indent}    {propertyName}.Add({propertyEntry});");
+
+            source.AppendLine($"{indent}}}");
+        }
+
+        public void GenerateSerializationMethod(StringBuilder source, string indent, SerializableProperty property)
+        {
+            const string expectedRule = nameof(ListMigrationRule);
+            var ruleName = property.Rule;
+            if (expectedRule != ruleName)
+            {
+                throw new ArgumentException($"Invalid rule applied to property {ruleName}. Expecting {expectedRule}, but received {ruleName}.");
+            }
+
+            var ruleArguments = property.RuleArguments;
+            var listElementRule = SerializableMigrationRulesEngine.Rules[ruleArguments[1]];
+            var listElementRuleArguments = new string[ruleArguments.Length - 2];
+            Array.Copy(ruleArguments, 2, listElementRuleArguments, 0, ruleArguments.Length - 2);
+
+            var propertyName = property.Name;
+            var propertyEntry = $"{char.ToLower(propertyName[0])}{propertyName.Substring(1, propertyName.Length - 1)}Entry";
+            source.AppendLine($"{indent}writer.WriteEncodedInt({propertyName}.Count);");
+            source.AppendLine($"{indent}foreach (var {propertyEntry} in {propertyName})");
+            source.AppendLine($"{indent}{{");
+
+            var serializableListElement = new SerializableProperty
+            {
+                Name = propertyEntry,
+                Type = ruleArguments[0],
+                Rule = listElementRule.RuleName,
+                RuleArguments = listElementRuleArguments
+            };
+
+            listElementRule.GenerateSerializationMethod(source, $"{indent}    ", serializableListElement);
+
+            source.AppendLine($"{indent}}}");
+        }
+    }
+}