[BB-1054] Wait for registration validation in browser tests instead of sleeping unconditionally
Created by: jamestait
Description
Adds to the Registration browser tests a custom WebDriver wait based on the Angular validation classes applied to server-side validated fields, and uses that with a longer timeout instead of an unconditional sleep.
Testing
- Browser tests ran by CircleCI must pass :)
Bonus: In a local devstack, run the browser tests multiple times to make sure there's no flakiness any longer. (I did this already)