Have good support for Views with non-nullable foreign key relationships

Exposing non-nullable table columns in views has been asked before ( and the current guidance is "It's a Postgres limitation, we have to workaround it". However, even if Postgres doesn't support it, it would be nice if supabase's type generation had a special carve-out for it.

Our current workaround is to cast the columns into non-nullable types like

This works, but now the foreign key relationship is destroyed and PostgREST is unable to find the relationship between active_posts and users.