Add JsonAssetReference type for scripting

Source/Engine/Content/JsonAssetReference.h

@@ -0,0 +1,25 @@
+// Copyright (c) 2012-2023 Wojciech Figat. All rights reserved.
+
+#pragma once
+
+#include "Engine/Content/JsonAsset.h"
+#include "Engine/Content/AssetReference.h"
+
+/// <summary>
+/// Json asset reference utility. References resource with a typed data type.
+/// </summary>
+/// <typeparam name="T">Type of the asset instance type.</typeparam>
+template<typename T>
+API_STRUCT(NoDefault, Template, MarshalAs=JsonAsset*) struct JsonAssetReference : AssetReference<JsonAsset>
+{
+    JsonAssetReference& operator=(JsonAsset* asset) noexcept
+    {
+        OnSet(asset);
+        return *this;
+    }
+
+    operator JsonAsset*() const
+    {
+        return Get();
+    }
+};