Bug 31559: Staff results page doesn't always use up full available screen width

Bug 31559: Staff results page doesn't always use up full available screen width

This patch adds an explicit "width: 100%" to tables which are contained
within a #searchresults <div>. The change affects staff interface
catalog search results and these other pages with the same markup:

- Advanced MARC editor search results
- Holds to pull
- Patron search results

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

- Test the catalog search results and other affected pages to confirm
  that the tables affected take up the full width of the page.

Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>