Create orgs and users that are missing in the mongodb

[Powersource]

Right now e.g. I don't exist in the prod plato-core db. Prod doesn't seem to crash though so that's fine for now. But we want orgs and users to exist there so we can properly use orgIds.

My thinking atm (middle of the night):

• Orgs: The single placeholder org we have now can be created in a db migration (built this for neo4j migrations but using it for mongo works fine as well I guess). Additional orgs we'll worry about when we add ui for creating those
• Users: Create them in the same place we're creating them for neo4j (i.e. in auth-callback. make sure to not run it if we don't have an orgId(silent refresh), we want the user to have an org)

[Powersource]

Confirmed it seems to create orgmembers! (although can't test if it will create multiple per user so far)