added first selectable, and modyfiable assets to system, Mesh, Material, and Texture. Texture ist WIP, because no subassets are created jet, well technicaly everything is WIP bit nevermind XD

TSE_Core/src/elements/Material.hpp

@@ -46,6 +46,8 @@ namespace TSE
             void SaveAsset() override;
             nlohmann::ordered_json GenerateMaterialJson();
             void Hash() override;
+            string assetType() override;
+            void UnloadAsset() override;
         protected:
             void SaveMeta() override;
     };