Enrollment errors should redirect user to the Payment Error page / retry view

[thekaveman]

This is a follow-up to the design work from #1137 and a prerequisite to the new designs coming with #1865. This is related to the refactoring happening in #1848.

We already have the enrollment:retry view implemented with the associated design for the Payment Error page in Figma.

This task is to ensure that any error raised during the enrollment process sends the user to this retry view instead of the generic application error view.

Acceptance Criteria

• Errors raised during enrollment are handled by the retry view/page instead of the generic app "Service Down" error page

[thekaveman]

We're doing a separate handoff for the new error screens, with tickets that will supersede this one.