decouple playgroups from tracks
-
use the playgroup name everywhere, not the track name -
still offer automatically creating a playgroup when creating a track (opt out) -
allow adding playgroups separately -
allow deleting playgroups separately (offer deleting associated persons, opt in - otherwise set their playgroup_id to None) -
when deleting a track, set the track_id of the associated playgroups to None -
visually distinguish playgroups without track / persons without playgroup / tracks without playgroups from those with them