Bug 32926: Add Selenium tests

Bug 32926: Add Selenium tests

This adds a new Selenium test to automatically test the correct
behaviour when expanding/collapsing System preferences sections
after a System preferences search.

Test plan:

1) Apply the other patch from this bug report, then run the
   new Selenium unit test which should pass without failures:

   prove -v t/db_dependent/selenium/system_preferences_search.t

Signed-off-by: Fridolin <fridolin.somers@biblibre.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>