Start pools even if user isn't in user table

[chasers]

• Use some "default user pool config" with a pool_size
• pool_type should be based on port maybe - 5432 = session and 6543 = transaction
• Flag on tenant record for require_user and if require_user is false we allow user creds to pull from connection string or other method
• require_user field default false
• Authentication of user to tenant database will happen on pool start and error to client if auth fails
• tenant username and pass stored in Cachex
• Docs - overview of this behavior
• Docs - tell people what happens if they change username/pass in tenant db
• Docs - example auth user query

[darora]

I think you'll also require some info (e.g. creds) to verify the client creds?

This is how we configure pgbouncer: https://github.com/supabase/postgres/blob/develop/ansible/files/pgbouncer_config/pgbouncer.ini.j2#L115-L124