Bug 10834 - Add Sort 1 and Sort 2 to list of searchable patron fields

Bug 10834 - Add Sort 1 and Sort 2 to list of searchable patron fields

Some libraries would like to be able to search on the sort1 and sort2
fields of patron records.

Test Plan:
1) Apply this patch
2) Add various values for sort1 and sort2 some patrons
3) Browse to members-home.pl
4) Run searches on sort1 and sort2

Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>
Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>
(cherry picked from commit 53c4129027f7d996c763da31303173c8b134a67a)
Signed-off-by: Fridolin SOMERS <fridolin.somers@biblibre.com>