Import labels

[simonv3]

Is there anything in place to actually track user group membership of itself? For example, artists being part of labels? As part of this, it kind of looks like a lot of the migrations into the DB that are labeled as "Label" are actually artists.

Edit: made the decision to do the following:

1. Create a user_group_members table.
2. on import from user-api db, import all user_groups as artists.
3. fetch all labels from rsntr_usermeta meta_key = 'mylabel'. This gives values user_id (member) of meta_value (label).
4. Find the label by user_group.legacy_id. Change that label to be of type label (3).
5. Find the artist by user_group.legacy_id. Insert them into the user_group_members table.