Bug 11218: Regression tests for Due notice generation

Bug 11218: Regression tests for Due notice generation

Changes tests for GetUpcomingDueIssues:

days_in_advance should be inclusive:
 2 should find items due in 2 days from now.
 1 should find items due tomorrow.
 0 should only find items due today.

Adds new tests for Bug 11218:

As the advance_notices.pl, the only script using GetUpcomingDueIssues
is not only used for PREDUE notices, but also for
DUE notices, we need to also select items due today.

Signed-off-by: Liz Rea <liz@catalyst.net.nz>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>
Rebased for 3.12.x