Bug 34323: Enhance header search icon for more options

Bug 34323: Enhance header search icon for more options

This patch modifies header search forms which have a "more options"
icon, adding a title attribute to the control and "aria-hidden" to the
Font Awesome icons.

I've added a bit of CSS and JS to change the appearance of the icon when
it is clicked to expand the panel of options.

To test, apply the patch and rebuild the staff interface CSS.

- Test pages which have a "more options" icon in the search header:
  - Home -> Catalog search tab, with IntranetCatalogSearchPulldown
    enabled.
  - Acquisitions -> Orders search tab
  - Authorities -> All search tabs
  - Administration -> Budgets
  - Patrons -> Patron search tab
  - Serials -> Subscription search tab
- On all these pages, hovering your mouse over the icon in the search
  form should trigger a "More options" title.
- Clicking the icon should expand the panel, and the icon should be
  now have a highlighted style.
- Clicking the icon to collapse the panel should return the icon to its
  original state.

Signed-off-by: Sam Lau <samalau@gmail.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>