fix(core): Fixes accounts and moves it to codegen (#644)

- [X] Fixes TimeSpan not working with codegen
- [X] Fixes bad check for generic classes with a serialize method and deserialize ctor
- [X] Moves Accounts to codegen so it is versioned
- [X] Fixes deserialization of old Accounts with no version variable.
- [X] Fixes deserialize seek not doing anything. 🙈 
- [X] Adds Email to serialization

Projects/Server/IAccount.cs

@@ -95,7 +95,7 @@ namespace Server.Accounting
         long GetTotalGold();
     }
 
-    public interface IAccount : IGoldAccount, IComparable<IAccount>, ISerializable
+    public interface IAccount : IGoldAccount, IComparable<IAccount>
     {
         string Username { get; set; }
         string Email { get; set; }

Projects/Server/Serialization/BufferReader.cs

@@ -164,6 +164,8 @@ namespace Server
                 throw new ArgumentException($"BufferReader does not support {nameof(offset)} beyond Int32.MaxValue");
             }
 
+            _position = (int)position;
+
             return _position;
         }
     }