Add musicbrainz integration

[fsdmu]

Add an integration to automatically set metadata using musicbrainz.

1. Check if there are open downloads in me tube.
2. Add metadata tags.
3. Check if songs in an album have duplicate number (position of song in album). Songs regularly get the number 63 (I think) instead of the actual position in the album.
4. check if there are open downloads and add handling for this
5. mount music dir in Dockerfile/TruenasScale (files are downloaded in top level dir and then should be moved to dir/music; evaluate whether move should happen manually or automatically.

[fsdmu]

5:
I think it should happen manually for now since often albums cant be recognized. If this can be handled !accurately! it should happen automatically.