Bug 38638: Offer non-priority option when placing multiple holds

This patch adds a checkbox for setting holds as non-priority when
placing multiple holds at once.

To test, apply the patch and make sure the DisplayMultiPlaceHold system
preference is enabed.

- Perform a catalog search in the staff client which will return
  multiple results.
- Check the checkboxes for 2 or more titles in the results and click
  "Place hold" in the toolbar.
- When confirming the holds, check the "Non priority hold" checkbox.
- Confirm that the holds are saved as non priority holds.
  - You can check by viewing the list of holds on a title. The "Details"
    column for that hold should say "Non priority hold."

Sponsored-by: Athens County Public Libraries
Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Andrew Fuerste Henry <andrew@bywatersolutions.com>
Signed-off-by: Pedro Amorim <pedro.amorim@openfifth.co.uk>

koha-tmpl/intranet-tmpl/prog/en/modules/reserve/request.tt

@@ -1199,6 +1199,12 @@
                             <input id="expiration_date" name="expiration_date" id="to" size="10" type="text" class="flatpickr" data-flatpickr-futuredate="true" />
                         </li>
 
+                        <li id="non_priority_list_item">
+                            <label for="non_priority">Non priority hold:</label>
+                            <input name="non_priority" id="non_priority" type="checkbox" />
+                            <span class="hint">A non priority hold doesn't prevent a current checkout from renewing</span>
+                        </li>
+
                         [% IF ( Koha.Preference('DisplayAddHoldGroups') ) %]
                             <li id="hold_group_list_item">
                                 <label for="hold_group">Treat as hold group: </label>