Update registration page for closed and newuser password systems

Styles the newuser password prompt the same as all the other text fields on the form, and also moves it to the top of the form (no point for a user to fill out the rest of the form once they realize they don't have the newuser password).

Also hides the form and rejects submission attempts for closed systems.

assigned to @echicken

approved this merge request

merged

mentioned in commit b98bdb18