Fix editing permissions

Originally sparked by https://github.com/fle-internal/ka-lite-central/issues/169 on the central server repo, this fixes that issue -- so now on central, admins can access / edit data for the orgs they are a part of, and students can still safely edit their own accounts. 
What's the difference between `user` vs. `facility_user_id`? Can they not be one and the same?