LP#2019032: restore functionality of two line item actions

LP#2019032: restore functionality of two line item actions

The "Add Brief Record" and "Load Bibs and Items" actions in the
Angular line item manager stopped working after the upgrade
to Angular 15. It turns out that the routerLink values associated
with those two actions were always incorrect, but for some
reason Angular 12's router worked around the error. Angular 15
does not, hence this patch.

To test
-------
[1] Navigate to a pending purchase order.
[2] Attempt the "Add Brief Record" and "Load Bibs and Items" items
    from the Actions drop-down. Note that the request forms
    do not display and the purchase order title becomes
    "Purchase Order #NaN (pending)".
[3] Apply the patch and repeat step 2. This time, the two
    actions should bring up the correct forms.

Signed-off-by: Galen Charlton <gmc@equinoxOLI.org>
Signed-off-by: Jason Boyer <JBoyer@equinoxOLI.org>
Signed-off-by: Jeff Godin <jgodin@tadl.org>