Bug 29922: Make get_search_groups return results sorted by title

Bug 29922: Make get_search_groups return results sorted by title

get_search_groups from Koha/Library/Groups.pm returns library groups sorted by title.

Test plan:
1- Go to administration > library groups and create multiple library groups with different names (e.g. AGroup, BGroup, ÄGroup, etc.). Make sure to tick "Use for OPAC search groups" checkbox.
2- Go to advanced search in OPAC.
3- Under "Groups of librairies" , click the select button.
4- Notice that the library groups are not in alphabetical order.
5- Apply the patch.
6- Notice that the library groups are in alphabetical order.
7- Run `prove t/db_dependent/LibraryGroups.t` and all test should pass.

Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>