Add Endpoint for user to delete all their data

[jayceslesar]

I think it is wise to include an endpoint for a user to wipe all of their data from the DB, either facilitated by an admin, or the user themselves, as an instant and irreversible action.

@kavorite @lili7h this one is a little tricky as this could be large amounts of data -- worth figuring out how we can sample what we need on the fly during ingestion to trim the fat as soon in the pipeline as posslbe