Current behaviour: when editing the artist field and not selecting any artist suggested in the dropdown menu, the association with the old artist is preserved.

Expected behaviour: the user should be forced to select one of the entries from the dropdown menu when the artist field is edited.

Entering a different artist name and not selecting a different artist makes the release editor behave as if the value was entered in the artist name variation field, which it shouldn't do.

See also MBS-2207 for a possible consequence of this behaviour.