Bug 33381: Fix sidemenu active and hover styling

Bug 33381: Fix sidemenu active and hover styling

Change router link active class match rule. This makes it so that the route erm/agreements/1 will also match the router-link /erm/agreements instead of the previous exact match rule, thus adding the 'current' class
Update styling router-links to not apply 'current' styling when
.disabled

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
(cherry picked from commit 92e3793eb87485a5726cd26bd1c567ca574b2760)
Signed-off-by: Jacob O'Mara <jacobomara901@gmail.com>