Downgrade Family pack to Basic or Complete
This MR contains the following changes:
- Properly deal with Family pack downgrades by downgrading invitees to Basic bundle.
- Refuse to downgrade Family pack if invitees don't have a recovery email set.
- Create Invitee subscription for new invitees when they set their recovery email.
- Move user related methods from limitmonitor.common to purist.models module.
- Add methods to create orders and subscriptions.
- process_renewals() now also deals with invitees.
Creation and management logic for INVITED accounts have change completely. Before this MR invited accounts copied services status (except the GROUP service) from the owner account. Now the invitees have their own subscription.
This implies that we need to create a new subscription variation in WC and also update the file