Add support for compiling and running engine without C# scripting

(configurable via `EngineConfiguration.UseCSharp` in Flax.Build)

Source/Engine/Scripting/BinaryModule.h

@@ -290,15 +290,19 @@ public:
     /// </summary>
     MAssembly* Assembly;
 
+#if !COMPILE_WITHOUT_CSHARP
     /// <summary>
     /// The scripting types cache that maps the managed class to the scripting type index. Build after assembly is loaded and scripting types get the managed classes information.
     /// </summary>
     Dictionary<MonoClass*, int32, HeapAllocation> ClassToTypeIndex;
+#endif
 
     static ScriptingObject* ManagedObjectSpawn(const ScriptingObjectSpawnParams& params);
     static MMethod* FindMethod(MClass* mclass, const ScriptingTypeMethodSignature& signature);
+#if USE_MONO
     static ManagedBinaryModule* FindModule(MonoClass* klass);
     static ScriptingTypeHandle FindType(MonoClass* klass);
+#endif
 
 private: