Reconsider `SubscriptionStatus` names

[FranjoMindek]

Now that we have access to more payment processors we should reconsider our SubScriptionStatus names to something more general.
Currently we have:

export enum SubscriptionStatus {
  PastDue = 'past_due',
  CancelAtPeriodEnd = 'cancel_at_period_end',
  Active = 'active',
  Deleted = 'deleted',
}

Deleted is an offender here because we use it to represent "Canceled" subscription state.
This is even more of a problem because some payment providers support both "Canceled" and "Deleted" states (e.g. Stripe in sanbox mode).