[Milestone] AssemblyLoader completed.

Details:
- Assembly Mgmt Service for loading now a separate interface, not intended for normal use.
- Assembly Loader work; implemented custom dictionary key and table.
- Assembly loading work.
- EventService completed.
- Moved assembly extensions to ModUtils.cs
- Work to event service.
NetworkService work
- Added ImpromptuInterfaces package.
- Networking Service work to support NetVars
- Event Service
- Added assemblies references package for script compilation. Updated Roslyn version for compatibility.
- Package Loading work.
Swap Harmony to HarmonyX
- More refactor conversion to FluentResults.
- Updated StylesService to return Results.
- Refactor of PackageService partially complete.
- Made IService.Reset() required to return a Result.
- Moved plugin/assembly related code to their own folder (same namespace).
- Updated interfaces to reflect the use of Result<T>.
- Partial refactor, incomplete.
- Added 'FluentResults' so we can stop using cursed Exception-based flow control in loading code.
- Added 'OneOf' nuget package: https://github.com/mcintyre321/OneOf
for the implementation of the Optional<T> pattern and complex discrete return types instead of cursed enums (see current AssemblyManager.cs).
- Reapplied old branch changes.

Barotrauma/BarotraumaClient/ClientSource/LuaCs/Services/IStylesService.cs

@@ -4,7 +4,7 @@
 /// <summary>
 /// Loads XML Style assets from the given content package.
 /// </summary>
-public interface IStylesService : IService
+public interface IStylesService : IReusableService
 {
     /// <summary>
     /// Tries to load the styles file for the given contentpackage and path into a new UIStylesProcessor instance.
@@ -12,11 +12,11 @@ public interface IStylesService : IService
     /// <param name="package"></param>
     /// <param name="path"></param>
     /// <returns></returns>
-    bool TryLoadStylesFile(ContentPackage package, ContentPath path);
+    FluentResults.Result LoadStylesFile(ContentPackage package, ContentPath path);
     /// <summary>
     /// Unloads all styles assets and UIStyleProcessor instances.
     /// </summary>
-    void UnloadAllStyles();
+    FluentResults.Result UnloadAllStyles();
     
     /// <summary>
     /// Tries to the get the font asset by xml asset name, returns null on failure.