MBS-13108: Require relationship editor, not admin, privs for attributes

[reosarevok]

Implement MBS-13108

Description

There's no real reason editing attributes such as activating languages or adding entity types should be locked behind account_admin. It has nothing to do with accounts nor private data, and a lot to do with schema / style, which is what we generally use relationship_editor for (not just relationships but also genres, instruments).

Testing

Edited the test requiring account_admin to require relationship_editor instead.

Notes

On top of https://github.com/metabrainz/musicbrainz-server/pull/3115