Bug 29015: (follow-up) Show sidebar filter form with results

Bug 29015: (follow-up) Show sidebar filter form with results

This patch adds the new filter form in the sidebar when showing results.
To do so the form markup is moved into a BLOCK so that it can be reused.

This patch also adds pre-selection of submitted options on the filter
form so that it reflects the user's choices.

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).

- Go to Circulation -> Holds queue.
- Submit the form with one or more filters selected.
- On the results page the queue should be correctly filtered and the
  sidebar should show your search fields preselected.
- Test with the CircSidebar preference enabled and disabled. The
  circulation menu should appear correctly, with the filter form only
  displaying in the sidebar after submitting the form.

Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>