Bug 27582: Fix breadcrumb for POS > Library details page

Bug 27582: Fix breadcrumb for POS > Library details page

This patch adds a link back to the top level 'Point of sale' page in the
breadcrumb for the 'Library details' summary page.

Test plan
1/ Enable 'UseCashRegisters' and 'EnablePointOfSale'
2/ Navigate to 'Point of sale' > 'Library details'
3/ Note the breadcrumb now includes the unlinked' Library details' page
title and a linked 'Point of sale' in the list.
4/ Signoff

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>