rurumi0318

Add JSON serialization support for GameplayTag and GameplayTagContainer

1

**Fix #16** Add `GameplayTagJsonConverter` and `GameplayTagContainerJsonConverter`. They use the same format as Unreal's convertion of `FGameplayTag` and `FGameplayTagContainer` ### Formats GameplayTag ``` { "tagName": "ParentTagA.Middle.LeafA" } ``` GameplayTagContainer ``` {...

GameplayTag and GameplayTagContainer can't be serialized to JObject with Newtonsoft Json, one of the built-in package. ``` [System.Serializable] public class MyClass { public GameplayTag tag; public GameplayTagContainer tagContainer; } JObject.FromObject(myClassInstance);...