fix(core): Optimizes strings / .NET 5 compatibility changes (#354)

- [X] Removes some string allocations (e.g. split)
- [X] Optimizes some collections
- [X] Converts insensitive to extension methods of built-ins.
- [X] Adds ordinal (case sensitive) string helpers
- [X] Fixes conditionals for in-game commands so they use Ordinal comparisons.
- [X] Replaces ToLower.Contains with InsensitiveContains
- [X] Adds ValueStringBuilder
- [X] Implements ValueStringBuilder in a few places where it makes sense
- [X] Removes the redundant Wrap function and replaces it with an optimized version
- [X] Fixes list conversions in Utility

Closes #351

Bumps release version

Projects/Benchmarks/BenchmarkUtilities/BenchmarkStringHelpers.cs

@@ -0,0 +1,87 @@
+using System.Buffers;
+using System.Text;
+using BenchmarkDotNet.Attributes;
+using BenchmarkDotNet.Jobs;
+using Server.Buffers;
+
+namespace Benchmarks.BenchmarkUtilities
+{
+    [MemoryDiagnoser]
+    [SimpleJob(RuntimeMoniker.NetCoreApp50)]
+    public class BenchmarkStringHelpers
+    {
+        private readonly string[] names =
+        {
+            "Kamron", "Owyn", "Luthius", "Jaedan", "Vorspire", "other people",
+            "Kamron-2", "Owyn-2", "Luthius-2", "Jaedan-2", "Vorspire-2", "other people too"
+        };
+
+        private int length;
+
+        [GlobalSetup]
+        public void Setup()
+        {
+            var chrs = ArrayPool<char>.Shared.Rent(65535);
+            ArrayPool<char>.Shared.Return(chrs);
+            length = 0;
+
+            for (int i = 0; i < names.Length; i++)
+            {
+                length += names.Length;
+            }
+
+            length += 2 * (names.Length - 1) + 3;
+        }
+
+        [Benchmark]
+        public string BenchmarkStringBuilder()
+        {
+            var sb = new StringBuilder();
+            for (var i = 0; i < names.Length; i++)
+            {
+                if (i > 0)
+                {
+                    sb.Append(i == names.Length - 1 ? ", and" : ", ");
+                }
+
+                sb.Append(names[i]);
+            }
+
+            return sb.ToString();
+        }
+
+        [Benchmark]
+        public string BenchmarkValueStringBuilderWithStack()
+        {
+            using var sb = new ValueStringBuilder(stackalloc char[length]);
+            for (var i = 0; i < names.Length; i++)
+            {
+                if (i > 0)
+                {
+                    sb.Append(i == names.Length - 1 ? ", and" : ", ");
+                }
+
+                sb.Append(names[i]);
+            }
+
+            return sb.ToString();
+        }
+
+        [Benchmark]
+        public string BenchmarkValueStringBuilderWithRentedBuffer()
+        {
+            using var sb = new ValueStringBuilder(stackalloc char[32]);
+            for (var i = 0; i < names.Length; i++)
+            {
+                if (i > 0)
+                {
+                    sb.Append(i == names.Length - 1 ? ", and" : ", ");
+                }
+
+                sb.Append(names[i]);
+            }
+
+            return sb.ToString();
+        }
+    }
+}