This PR adjusts the create billing subscription endpoint to prevent
initiating a checkout flow when a user has existing subscriptions that
are overdue.
A subscription is considered "overdue" when either:
- The status is `past_due`
- The status is `canceled` and the cancellation reason is
`payment_failed`
In Stripe, when a subscription has failed payment a certain number of
times, it is canceled with a reason of `payment_failed`. However, today
there is nothing stopping someone from simply creating a new
subscription without paying the outstanding invoices. With this change a
user will need to reconcile their outstanding invoices before they can
sign up for a new subscription.
Release Notes:
- N/A
a4dd92fe06