Made a change to serialize resource paths as regular file paths instead of UIDs.

UIDs only support in editor referencing of resources so when a game is exported, UID paths become invalid. So the only out of the box option is file paths unfortunately.

I kept an option for a Placeable to add the UID to the serialize dictionary on get_load_data(p_include_uid : bool) but this data is only useful within the game editor for now.

With UID off by default, demo project save files now look like this after saving to JSON