Bug 34608: Add sort1 and sort2 to patron search results

Bug 34608: Add sort1 and sort2 to patron search results

This patch adds the option of displaying patron "sort1" and
"sort2" statistical fields in the patron module's main search
results. The fields are hidden by default in the updated table
configuration.

To test, apply the patch and restart services.

- Go to Patrons and perform a search.
- You should not see columns for sort1 and sort2.
- Under the "Columns" button you should see options to display sort1 and
  sort2. Confirm that they work to show and hide the columns.
- Confirm that the sort1 and sort2 columns are sortable and searchable.

- Go to Administration -> Table settings.
- Under Patrons -> member, toggle the sort1 and sort1 "hidden by
  default" checkboxes and save the configuration.
- Return to patron search results to confirm that the columns are now
  shown by default.

Signed-off-by: Émily-Rose Francoeur <emily-rose.francoeur@inLibro.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>