Get album art from musicbrainz_albumid tag

[G2-Games]

The album art lookup seems to fail often even on albums which have existing album art in Musicbrainz. Most of my songs are tagged with Picard, so looking up the MBID from the musicbrainz_albumid tag would be a better way of searching for album art.

More information here: https://picard-docs.musicbrainz.org/en/variables/tags_basic.html