Bug 19401: Add confirm message when deleting invoice

To test:
1) Go to Acquisitions
2) Go to Invoices (left nav menu)
3) Click Search (no need to filter results)
4) Click dropdown menu for an invoice, click Details
5) Click Delete
6) Notice invoice is deleted instantly
7) Apply patch and repeat steps 4 and 5
8) Confirm the confirm message shows and works as expected

Sponsored-by: Catalyst IT

Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>

Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>

Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
(cherry picked from commit 128d163e1b)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>

koha-tmpl/intranet-tmpl/prog/en/modules/acqui/invoice.tt

@@ -23,6 +23,9 @@
     }
 
     $(document).ready(function() {
+        $("#delete").click(function(){
+            return confirmDelete(_("Are you sure you want to delete this invoice?"));
+        });
         $("#orderst").dataTable($.extend(true, {}, dataTablesDefaults, {
             bInfo: false,
             bPaginate: false,
@@ -123,7 +126,7 @@
         <fieldset class="action">
             <input type="submit" value="Save" />
             [% UNLESS orders_loop.size %]
-            <a href="invoice.pl?op=delete&invoiceid=[% invoiceid %]">Delete</a>
+            <a href="invoice.pl?op=delete&invoiceid=[% invoiceid %]" id="delete">Delete</a>
             [% END %]
         </fieldset>
       </form>