Bug 29100: Add checkouts data loop to predue notices script ( advance_notices.pl )

Bug 29100: Add checkouts data loop to predue notices script ( advance_notices.pl )

Predue / due notices are limited to using itemscontent to display checkouts data. It would be nice to make all the checkouts data available for those notices so that libraries could format that data more nicely if they wish.

1) Apply this patch
2) For DUE and PREDUE notices, set the message body to the following:
Title: [% issue.title %]
3) For DUEDGST and PREDUEDGST notices, set the message body to the following:
Titles:
[% FOREACH i IN issues %]
* [% i.title %]
[% END %]
4) Generate PREDUE and DUE notices for patrons including digests
5) Verify those notices contain the checkout titles

Signed-off-by: Felicity Brown <Felicity.Brown@montgomerycountymd.gov>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>