* Remove image and animation_url from metadata modal
* Use animation_url for storing audio and video asset URIs
* Use image and animation_url keys together for audio/video assets
* Delete empty metadata keys
* Post-review update
* Add animation_url and youtube_url to metadata modal
* Reset asset and metadata list on upload method change
* Allow the user to add attributes even though the metadata file is missing them
* Add missing attribute check
Co-authored-by: findolor <anakisci@gmail.com>