Bug 35127: Fix 'Search type' for patron search

Bug 35127: Fix 'Search type' for patron search

We need to fallback on the syspref DefaultPatronSearchMethod but keep
the value when one is passed!

Test plan:
Search for patrons, and use the "search type". Set it to different
values than DefaultPatronSearchMethod and confirm that the value is
kept.
Fix is expected when searching for patrons in the header (use the
options to select a different value and run the search)

Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>