Submission pages are broken

[omnicons]

It seems that no one including myself can submit things, Song Submission and Artist Submission are the two tested functions that seem to be having problems.

Things to fix (added by @Feld0):

• have the artist profile submission page recognize if you've already submitted a profile and offer you the ability to edit it instead of letting you submit another profile

[EventideGlow]

At least part of the problem here is that the artists table has a unique constraint on the user_id column, effectively preventing the submission of more than one artist profile per account.

The method of editing a profile that has already been submitted is not obvious, and may not even exist for an unapproved profile. The user who reported this wished to make some changes to their still-pending profile and thought the way to do that was to re-submit their profile, only to get a SQL error about the unique constraint.