Bug 37159: Updated tab style

Bug 37159: Updated tab style

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 plan
1) Confirm the styling change for top level tabs on patron details or catalog
   details pages.
2) Confirm the styling change is ok for a nested set of tabs (catalog
   holds page is a good example).

Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
https://bugs.koha-community.org/show_bug.cgi?id=31759

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