Quick new modal still not submitting on CAS [v5.5]

[orenyk]

While we were able to fix the quick new modal form in #1421, the form does not submit on DEV with a generic "Please correct the errors below" message but no fields displaying errors. I suspect this might have something to do with the difference between CAS / non-CAS, either in the form partial and/or in the controller quick_create method - we should fix this ASAP.

[orenyk]

Going to fix this and merge into release-v5.5 immediately so we can deploy v5.5.4, we'll have it reviewed properly for master.

[orenyk]

Fixed it, also ended up resolving #1469 so I'll bundle that in here.

[orenyk]

Also, wow, our test suite totally fails when we have CAS enabled.