Bug 15760: Fix order by direction for shelves

Bug 15760: Fix order by direction for shelves

The order_by parameters should not be "$direction $order_by" with
quote_names enabled. The correct syntax is { -$direction => $order_by }

Test plan for Opac + Staff interfces:
Sort list by title or whatever and change the direction

Signed-off-by: Mirko Tietgen <mirko@abunchofthings.net>
Signed-off-by: Tomas Cohen Arazi <tomascohen@unc.edu.ar>
Signed-off-by: Brendan Gallagher brendan@bywatersolutions.com