Bug 20212: Controller changes regression tests

Bug 20212: Controller changes regression tests

This patchset did a copy and paste of the objects->search helper inside
the controller, to handle a very special case that wasn't worth
generalizing: the fact that the biblio object (that this patchset makes
embeddable) is actually built from two tables, and we want to filter by
fields in both tables.

This requires us to translate:
- Any filter reference to fields in biblioitems we allow to search on, through
  an allow list.
- For filtering to work, we need to tweak the stashed 'embed' object so
  the prefetch is done correctly

This patchset also adds a new query parameter: only_active. It is used
to only request active orders (see the spec for more details).

This patch adds tests for:
- Filtering by a column in bilbioitems (this implies correctly
  prefetching the bilbio => biblioitems relation, and translating the
  filtering parameter.
- Using the only_active query parameter to retrieve only active orders

To test:
1. Apply this patchset
2. Run:
   $ kshell
  k$ prove t/db_dependent/api/v1/acquisitions_orders.t
=> SUCCESS: Tests pass!
3. Verify the tests check for the explained behaviours.
=> SUCCESS: They do!
4. Sign off :-D

Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Andrew Fuerste-Henry <andrew@bywatersolutions.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>