TODO:
* Purge payments before billings to avoid removing a billing linked to an account_adjustment before the account_adjustment is deleted.
* Improve delete speed / disable triggers / consider truncate/rebuild of money.billing.
TODO:
* Purge payments before billings to avoid removing a billing linked to an account_adjustment before the account_adjustment is deleted.
* Improve delete speed / disable triggers / consider truncate/rebuild of money.billing.