Bug 25670: New orders included only if standing

Bug 25670: New orders included only if standing

The original implementation included new orders regardless they were
standing orders.

This patch makes the query respect that conditions found on
C4::Acquisitions::SearchOrders.

To test:
1. Apply the regression tests patch
2. Run:
   $ kshell
  k$ prove t/db_dependent/Koha/Acquisition/Orders.t
=> FAIL: More orders than expected are returned
3. Apply this patch
4. Repeat 2
=> SUCCESS: Tests pass! New orders are only considered if the basket
they are attached to, is marked as standing!
5. Verify the tests make sense
6. Sign off :-D

Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>