Pre-flight check for account deletion

Team workspaces the person is in. blocking: they are its last owner and others are in it, so closing is refused until someone else is an owner or it is deleted. deletedWithAccount: they are alone in it, so it is deleted with the account, subscription included. leaving: the rest, which they leave; the diagrams they made there stay. On a leaving team the person pays for, their card is removed from it when the account closes, and youPay names the remaining owner the billing contact moves to; every remaining owner is asked to add a card.