This ticket has two parts:

1. Link to ListenBrainz accounts from the MeB donor page, if the user has one (we already link MB accounts and LB is cool too)
2. While we're at it/changing the donor rows, let's make the username primary and the legal name secondary, e.g:

Currently:

Firstname Surname (username)

Propose:

username (MusicBrainz) (ListenBrainz)

Hovering over the question mark icon shows the legal name. Or have the legal name in a completely different column.

Happy for the MB and LB links to be icons, but insist on them being in a separate column in that case, as a jumble of un-aligned coloured icons will make things painful to look at.