Optimisation: When showing failed/failing invoices to subscribers, don't check the decline_code of paid invoices

[chrisjsimpson]

Is your feature request related to a problem? Please describe.
No need to check the decline_code of paid invoices (they're paid already).

Describe the solution you'd like

When showing failed/failing invoices to subscribers, don't check the status of paid invoices.

Describe alternatives you've considered

Additional context