LP#2019150: link to AngularJS Patron Requests interface

LP#2019150: link to AngularJS Patron Requests interface

Due to a presumed timing issue in 2018, the AngularJS patron purchase
request interface created in bug 1774277 was never linked to from the
Angular navbar (only the AngularJS one).

This patch fixes this.

To test
-------
[1] Apply the patch.
[2] From the Angular menu, go to Acquisitions -> Patron Requests
    and verify that it loads the AngularJS interface rather
    than the legacy Dojo one.

Signed-off-by: Galen Charlton <gmc@equinoxOLI.org>
Signed-off-by: Terran McCanna <tmccanna@georgialibraries.org>
Signed-off-by: Jane Sandberg <js7389@princeton.edu>