The table that is affected here was not properly purged of old entries. It only holds
data that is needed while a 3rd party authorization is in progress but not finished.
The code that typeorm generated for this migration is a bit wonky because it should
probably have dropped one column and created another one. But if we clear out all entries
it should work regardless and I'm feeling lazy right now. :P
This also simplifies API authentication a bit by not having to fetch
the App that is related to a token.
The restriction of 1 token per app is also lifted. This was not a
constraint in the database but it was enforced by the code and
kinda wrong schema the auth_session table had.