Bug 27440: Improve structure and style of result toolbars in the OPAC

Bug 27440: Improve structure and style of result toolbars in the OPAC

This patch makes markup and CSS changes to areas of the OPAC classed
with "selections-toolbar," an area of controls found at the top of some
lists of titles: The cart, search results, search history, lists, and
suggestions.

To test, apply the patch and rebuild the staff client CSS
(https://wiki.koha-community.org/wiki/Working_with_SCSS_in_the_OPAC_and_staff_client).

- Perform a search in the OPAC. On the search results page, confirm that
  the various controls work correctly:
  - With OpacHighlightedWords enabled, hightlight and unhighlight links
  - Select all and clear all links
  - Selecting one or more checkboxes should enable the "Select titles
    to..." menu.
    - Test that adding items to the cart and lists works correctly.
    - Test that placing multiple holds work.
    - Test that tagging multiple items works.
- From the search results page, add multiple items to the cart.
  - Open the cart and confirm that the the controls described above
    continue to work correctly.
- Open the search history page, confirm that the toolbar controls work
  correctly for all four categories: Current session catalog searches;
  previous session catalog searches; current session authority searches;
  previous session authority searches.
- On the purchase suggestions page, confirm that "select all" and "clear
  all" work, and that deleting multiple suggestions from the toolbar
  link works.
- On the list contents page test the same controls: selection,
  multi-hold, tagging, and "Remove from list."

Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>