Comment 5 for bug 1904036

Pushed a commit which groups the new experimental Angular interfaces into a single nav bar entry. The new entry is labeled "Circulation (Experimental)" and can be enabled via a new org unit setting "ui.staff.angular_circ.enabled".

This change makes the navigation a lot tidier.

I'm still working from user/berick/lp1904036-patron-ui-angular-v3