Bug 28261: Add visual feedback on overridden pickup locations on patron's page

Bug 28261: Add visual feedback on overridden pickup locations on patron's page

This patch makes the patron pages in the staff interface use the API and
Select2 to render the pickup locations list. This has the effect of
adding visual feedback on those pickup locations that need an override,
based on the current configuration options.

All the checks are done in the GET /holds/:hold_id/pickup_locations
route, so this is a fairly trivial change.

To test:
1. Have a couple holds for a patron, some overrriden, some not
2. Visit the patrons' detail page, holds tab.
=> SUCCESS: You see the holds, pickup location has a dropdown
3. Repeat in the circulation tab for the patron
=> SUCCESS: You see the holds, pickup location has a dropdown
4. Apply this patch
5. Repeat 2 and 3
=> SUCCESS: Same behavior as before, but the dropdown is rendered with
Select2 and has a search feature. Overridden pickup locations have an
icon telling so
6. Sign off :-D

Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>