Add support for musicbrainz

[scottmc]

There is a recipe for libmusicbrainz in haikuports. Suport for this could be added to HARE.
https://musicbrainz.org/doc/libmusicbrainz

[scottmc]

Support could be added in such a way that album artwork could be downloaded and added to newly ripped audio files.

[scottmc]

Musicbrainz support was added to ArmyKnife a few years ago, that might be a good reference for adding it to Hare.