Bug 26988: Add API route to fetch hold pickup locations and use it in the holds table

Bug 26988: Add API route to fetch hold pickup locations and use it in the holds table

To test:
1 - Place a number of holds on a record
2 - Have different pickup locations for the holds
3 - Have some libraries that are not pickup locations
4 - Load the holds tab for the record and note libraries not pickup locations are not in dropdowns
5 - Apply patch and restart all things
6 - Reload the holds table
7 - Click on a dropdown, note the spinner, should load successfully
8 - Confirm the dropdown matches the options before the patch
9 - Confirm updating the hold location works

Signed-off-by: Andrew Fuerste-Henry <andrew@bywatersolutions.com>
Signed-off-by: Bob Bennhoff <bbennhoff@clicweb.org>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>