fix(core): Updates expansion and map configurations (fixes map issues) (#570)

- [X] Adds question about expansion at start of server
- [X] Adds question about client version to determine old have and map diffs
- [X] Adds config setting "maps.enablePre6000Trammel"
- [X] Rearranges some of the loading order.
- [X] Added support for deserializing nullable enums from json

TODO:
Expand the nullable enums deserialization factory to work with any type by pulling the factory and creating an instance of the converter.

Projects/Server/Json/JsonConfig.cs

@@ -19,6 +19,7 @@ using System.IO;
 using System.Text.Encodings.Web;
 using System.Text.Json;
 using System.Text.Json.Serialization;
+using Server.Json.Converters;
 using Server.Text;
 
 namespace Server.Json
@@ -39,6 +40,7 @@ namespace Server.Json
                 Encoder = JavaScriptEncoder.UnsafeRelaxedJsonEscaping
             };
 
+            options.Converters.Add(new JsonNullableEnumConverterFactory());
             options.Converters.Add(new JsonStringEnumConverter());
             options.Converters.Add(new MapConverterFactory());
             options.Converters.Add(new Point3DConverterFactory());