Bug 30628: Fix patron selection in batch patron modification tool

Bug 30628: Fix patron selection in batch patron modification tool

bug 28014 added Datatables to this view, but the form is submitted with
only the checkboxes from the first page.

Solution adapted from https://stackoverflow.com/questions/33240409/how-to-submit-checkboxes-from-all-pages-with-jquery-datatables

Test plan:
Have more than 20 cardnumbers, use the batch patron modification tool
Select (not all) patrons from the first page and second page
Submit the form
Notice that the patrons you have selected appear on the confirmation
page.

Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>