Bug 9967 - Cache authorised value requests properly

Bug 9967 - Cache authorised value requests properly

Authorised values are now cached using the proper Koha::Cache mechanism,
rather than a simple internal cache. Memoize has been removed because it
didn't really work like we needed it to.

Test plan:
 * running a persistent environment:
 * load the edit item screen
 * refresh several times to ensure any process-based caches are filled
 * add a new LOC authorised value as fast as possible (prepare it on
   another tab.)
 * refresh the edit item page
 * note that the new LOC value may or may not be showing in the
   "shelving location"
 * if more than 5 seconds have passed since saving it, it must now show
   up.
 * refresh a few times to ensure that it's showing on all processes.

Note:
 * This patch depends on the caching changes of 9967.

Signed-off-by: Brendan Gallagher <brendan@bywatersolutions.com>
Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>