[WiP] Fix trial expiration

Separating plan_level from community to a new table for the sake of saving some data about when communities have changed their plan levels.
Shortly.
- Active flag breaks way too easily since our superadmin UI is direct access to db.
- There didn't seem to be any good reason to activate previously used plan. (we want to  keep record what has been the 'story' of different customers => record plan changes)