Fetch `remixer` field from MusicBrainz

Problem

Musicbrainz seems to have a field called remixer for remixes, this info isn’t written to my files.

Example: https://musicbrainz.org/release/7c7f7ddf-c021-4ee8-993d-d1c330b4a36a

Using it for the artist field, similarly to the artist_credit option would also be nice.

According to the Picard docs there would even be a proper place to store it in ID3.

Setup

• OS: Arch Linux
• Python version: 3.10
• beets version: 1.6.0
• Turning off plugins made problem go away (yes/no): no

[TypicalFence]

@Bootjewolf I just went over the musicbrainz api docs.

The remixer tag is a artist relation. When we include artist-rels in a request of a recording from the album we get the following: JSON, which includes a relation of the type remixer. 🎉

Now for that to work for the requests that you posted we need to include recording-level-rels, which just tells musicbrainz to resolve the rels on a recording (track/song) level.

This leaves us with the following url: https://musicbrainz.org/ws/2/release/7c7f7ddf-c021-4ee8-993d-d1c330b4a36a?inc=aliases%2Bartist-credits%2Blabels%2Bdiscids%2Brecordings%2Bartist-rels%2Brecording-level-rels&fmt=json

You can find this in the api docs here.

The api is rather complicated tbh.

[Bootjewolf]

According to my tests I have successfully implemented it in PR #4549.