Bug 24191: Make objects.search pass to_model to dbic_merge_sorting

This patch makes objects.search pass the to_mode method reference so it
can be used to map API attributes to column names when building the
sorting portion of the query.

To test:
1. Apply the regression tests on this patchset
2. Run:
  $ kshell
 k$ prove t/db_dependent/Koha/REST/Plugin/Objects.t
=> FAIL: Tests fail!
3. Apply the rest of the patchset
4. Run:
 k$ prove t/Koha/REST/Plugin/Query.t
=> SUCCESS: Tests pass! changes to the methods work as expected!
5. Run:
 k$ prove t/db_dependent/Koha/REST/Plugin/Objects.t
=> SUCCESS: Tests pass!
6. Sign off :-D

Sponsored-by: ByWater Solutions
Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Josef Moravec <josef.moravec@gmail.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>

Signed-off-by: Joy Nelson <joy@bywatersolutions.com>
(cherry picked from commit 32ded50691)

Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>
(cherry picked from commit 3de45aad29)
Signed-off-by: Hayley Mapley <hayleymapley@catalyst.net.nz>

Koha/REST/Plugin/Objects.pm

@@ -60,7 +60,8 @@ sub register {
             $c->dbic_merge_sorting(
                 {
                     attributes => $attributes,
-                    params     => $reserved_params
+                    params     => $reserved_params,
+                    to_model   => $to_model
                 }
             );