Bug 26023: Properly secure the cashup and refund actions

Bug 26023: Properly secure the cashup and refund actions

The cash register summary page for cash management is available for users
with the 'anonymous_refund' or 'cashup' permission and the actions available
are appropriately displayed.

However, the actions are not yet correctly tested for at the server and
so a user may force submit to accomplish the action.

Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>