ui: tests - add e2e test for "save" action on draft - required field

[pamfilos]

e.g. with CMS cadi:

1. Create record, don't fill up a required field, click save, it should work.
2. Then try to publish, it should throw an error (and indicators in tab view).

[miguelgrc]

It is currently possible to publish a draft with empty required fields. The validation only triggers when there's some change in the form before clicking on save or publishing. Is this a desired behavior? @pamfilos