Bug 40782: Selections toolbar checkbox now adds tabindex -1

This patch now sets tabindex to -1 if a disabled class is applied to a
control, and removes it when the class evaporates. This improves
accessibility by making these disabled items non-focusable.

To test:
a)  make a search on the OPAC
b)  tab through the selections toolbar, notice how visually disabled
    items are focusable
APPLY PATCH
c)  repeat steps a-b, notice how the elements are no longer focusable
SIGN OFF

Signed-off-by: Owen Leonard <oleonard@myacpl.org>

Bug 40782: (follow-up) Tidy results-list.js

Tidy converts single quotes to double quotes

Signed-off-by: Owen Leonard <oleonard@myacpl.org>

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>
(cherry picked from commit 0c6402b951)
Signed-off-by: Paul Derscheid <paul.derscheid@lmscloud.de>

koha-tmpl/opac-tmpl/bootstrap/js/results-list.js

@@ -34,9 +34,11 @@ function enableCheckboxActions() {
     if ($(checkedBoxes).size()) {
         $(".selections").html(__("With selected titles: "));
         $(controls).removeClass("disabled");
+        $(controls).removeAttr("tabindex");
     } else {
         $(".selections").html(__("Select titles to: "));
         $(controls).addClass("disabled");
+        $(controls).attr("tabindex", "-1");
     }
 }