Bug 17738: Replace GetReservesFromBorrowernumber with Koha::Patron->get_holds

Bug 17738: Replace GetReservesFromBorrowernumber with Koha::Patron->get_holds

This patch replace the different calls to GetReservesFromBorrowernumber
with a calls to Koha::Patron->get_holds.
In some places we need to get a restricted set of holds, that's why we
process a search on this holds returned by ->get_holds (on the found
status for instance).

The changes are quite trivial and reading the diff should be enough to
catch bugs.

Test plan:
I would suggest to test this patch with patches from bug 17736 and bug 17737,
to place different kind of holds (biblio and item level, future and
past).
Then do a whole workflow to detect bug, view a record, delete record,
order, place a hold on an item which has been ordered, etc.
The hold's informations should always be the same without or without
these patches.

Tested both patches together, works as expected.
Signed-off-by: Marc Véron <veron@veron.ch>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>