Bug 31797: Add DELETE /items/:item_id endpoint

Bug 31797: Add DELETE /items/:item_id endpoint

This patch adds the mentioned endpoint. The controller relies on
Koha::Item->safe_to_delete for checks and uses `safe_delete` as
additem.pl does.

The required permissions are edit_catalogue.

To test:
1. Apply this patch
2. Run:
   $ kshell
  k$ prove t/db_dependent/api/v1/items.t
=> SUCCESS: Tests pass!
3. Play with item deletion using a REST tool like Postman
=> SUCCESS: All works as expected
4. 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>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>