Bug 24159: Move useDaysMode pref to circulation rules

Bug 24159: Move useDaysMode pref to circulation rules

Moving the useDaysMode system preference to a circulation rule will add
much more flexibility in the calculation of the due date.

The initial request was to make hourly loan returned on closed when
(when checked out on the same close day).
To do so we do not want to take into account the calendar.
However the calendar need to be taken into account for other loan item types.

Other scenarios are possible, for instance depending on the branch.

This patchset will add a new "Days mode" column (next to "Loan period")
to the circulation rules page, with the different values of the
"useDaysMode" system preference + a "default" value, to default to the
system preference value.

Test plan:
- Define a long loan item type (like 10 days) that will use the calendar
(or default to the pref value, if the pref is not set to "ignore the
calendar")
- and a hourly loan (like 2 hours) that will ignore the calendar
- Create items with those item types
- Mark today as a closed day
- Check the items out
=> The hourly loan is due the same day
=> The other loan is due on an open day

QA note:
There is the need to force the "days_mode" option when Koha::Calendar is
initiated for the due date calculation. To make sure devs will not
forget it, the methods that need have it defined will throw an
exception.

Sponsored-by: Institute of Technology Carlow
Signed-off-by: Simon Perry <simon.perry@itcarlow.ie>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>