[ rebased 2022-07-18 ] Also adds a select all / clear all and checkboxes. Test plan: 1. start a new batch in the patron card creator (Tools -> Patron card creator -> New -> card batch) 2. click the Add patron(s) button. Observe that Category and Library are the only options. 3. Close search for patron window. 4. Apply patch. 5. click the Add patron(s) button. Observe that you can now search for patrons by their sort1 and sort2 values. 6. perform a search and observe the 'Select all | Clear all | Add selected patrons' links and button. 7. use the Select all link to select all the patrons found by the search. 8. use the Add selected patrons button to add the selected patrons to the card batch's Add by borrowernumber(s) text input field. 9. close the search for patron window.