Drop libraries in favor of playlist for user audio sharing (#2366)

api/funkwhale_api/cli/users.py

api/funkwhale_api/federation/activity.py

api/funkwhale_api/federation/api_serializers.py

api/funkwhale_api/federation/factories.py

..._api/federation/management/commands/fix_federation_ids.py

api/funkwhale_api/federation/routes.py

api/funkwhale_api/federation/serializers.py

api/funkwhale_api/federation/views.py

api/funkwhale_api/manage/serializers.py

api/funkwhale_api/moderation/serializers.py

api/funkwhale_api/music/fake_data.py

...album_artist_remove_track_artist_artistcredit_and_more.py

...ic/migrations/0060_remove_library_description_and_more.py

...pi/music/migrations/0061_migrate_libraries_to_playlist.py

api/funkwhale_api/music/models.py

api/funkwhale_api/music/serializers.py

api/funkwhale_api/music/spa_views.py

api/funkwhale_api/music/views.py

...le_api/playlists/migrations/0008_playlist_library_drop.py

api/funkwhale_api/playlists/models.py