Bug 23492: OPAC search facet header should not be a link at larger browser widths

Bug 23492: OPAC search facet header should not be a link at larger browser widths

This patch adds some JavaScript-driven "breakpoints" to the OPAC so that
on the search results page the "Refine your search" heading has
different behaviors depending on whether facets are being displayed as a
sidebar.

To test, apply the patch and regenerate the OPAC SCSS
(https://wiki.koha-community.org/wiki/Working_with_SCSS_in_the_OPAC_and_staff_client).

Go to the OPAC and resize your browser to be greater than ~ 800px wide.

 - Perform a catalog search which will return several results.
 - In the left-hand sidebar of the search results page, the "Refine your
   search" heading should not be styled like a link. Hovering over it
   with the mouse should not change the cursor to the pointing-hand.
 - Narrow your browser window until the sidebar collapses.
   - The "Refine your search" heading should now be styled as a link,
     with a right-arrow icon before it.
   - Clicking it should expand the facets. The icon should change to a
     down-arrow.
 - Widen your browser window and test again.

 - Perform the same tests when starting with a narrow browser window.

Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>