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/Server/Json/Converters/NullableStructSerializerFactory.cs

@@ -13,6 +13,8 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>. *
  *************************************************************************/
 
+using Server;
+
 namespace System.Text.Json.Serialization
 {
     public class NullableStructSerializerFactory : JsonConverterFactory
@@ -26,8 +28,7 @@ namespace System.Text.Json.Serialization
 
             var structType = typeToConvert.GenericTypeArguments[0];
             return !structType.IsPrimitive &&
-                   structType.Namespace?.StartsWith(nameof(System), StringComparison.Ordinal) != true &&
-                   !structType.IsEnum;
+                   structType.Namespace.StartsWithOrdinal(nameof(System)) && !structType.IsEnum;
         }
 
         public override JsonConverter CreateConverter(Type typeToConvert, JsonSerializerOptions options) =>