Summary:
This has no real behavioral changes (except better error handling), it just factors things out to be a bit cleaner. In particular:
- Move more shared form behaviors into the common JS form component.
- Move more error handling into shared pathways.
- Make the specialized Stripe / Balanced methods do less work.
This needs some more polish for nontrival errors (especially on the Balanced side) but none of the error behavior is worse than it was and a lot of it is much better.
Ref T2787.
Test Plan: Hit all invalid form errors, added valid payment methods with Stripe and Balacned.
Reviewers: btrahan, chad
Reviewed By: btrahan
CC: aran
Maniphest Tasks: T2787
Differential Revision: https://secure.phabricator.com/D5771
