Bug 36120: Add pickup locations to place bookings modal

Bug 36120: Add pickup locations to place bookings modal

This patch adds a call to /biblios/biblionumber/pickup_locations to
fetch valid pickup locations for the biblio.

Upon selecting a pickup location we adapt the item select to only allow
for selecting items returned as valid for pickup at the selected
location.

Sponsored-by: Cuyahoga County Public Library
Signed-off-by: Lisette Scheer <lisette.scheer@bywatersolutions.com>
Signed-off-by: Kristi Krueger <kkrueger@cuyahogalibrary.org>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>