Bug 21337: Add Koha::Patrons->delete (trivial wrapper)

Bug 21337: Add Koha::Patrons->delete (trivial wrapper)

Adds Koha::Patrons->delete as wrapper around Koha::Patron->delete. We do
not want to bypass Koha::Patron and let DBIx do the job without further
housekeeping. A call to move_to_deleted is included now, but could be
made optional with a parameter if needed.

Test plan:
Run t/db_dependent/Koha/Patrons.t

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Michal Denar <black23@gmail.com>
Signed-off-by: Michal Denar <black23@gmail.com>
Signed-off-by: Josef Moravec <josef.moravec@gmail.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>