Bug 26172: Add cashup summary view modal

Bug 26172: Add cashup summary view modal

This patch adds a cashup summary modal to the register details page.

Test plan
1/ Enable Cash Registers and Point of Sale
2/ Enable some debit_types as 'Sale items'
3/ Perform a series of transactions
4/ Perform a 'Cashup' on the register
5/ Note the new '(Summary)' link next to the last cashup on the register
page.
6/ Click the link and confirm the modal contains the pertinent
information

Signed-off-by: Sally <sally.healey@cheshiresharedservices.gov.uk>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>