Bug 24767: Hide the "Claim returned" tab if the feature is turned off

Bug 24767: Hide the "Claim returned" tab if the feature is turned off

The ability to claim an item "claim returned" is not there if the syspref is empty, however, the Claim Returned tab is stil present on the patrons detail page.

Test Plan:
1) Ensure ClaimReturnedLostValue is not set
2) Note the claims tabs on the circulation and patron details pages
3) Apply this patch
4) Refresh those pages
5) The claims tabs should be gone!

Signed-off-by: Sally <sally.healey@cheshiresharedservices.gov.uk>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>