Bug 30663: Implement overrides handling in POST /suggestions

Bug 30663: Implement overrides handling in POST /suggestions

This patch implements the override checks in the controller as expected
by the previous patch.

To test:
1. Apply this bug patches up to 'Add x-koha-override options...'
2. Run:
   $ kshell
  k$ prove t/db_dependent/api/v1/suggestions.t
=> FAIL: Tests fail! The controller doesn't care about overrides or
         sysprefs about suggestions limits.
3. Apply this patch
4. Repeat 2
=> SUCCESS: Things work!
5. Sign off :-D

Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>