Test: cts-scheduler: add test for "primitive with unrunnable group"

The essential elements of this test are:

• A primitive (rsc1) has a mandatory colocation with a group
• The group's start is blocked (in this case, because it has a mandatory ordering after another primitive with target-role=Stopped)

With the current code, rsc1 is wrongly allowed to start. (The current code
does correctly block rsc1 if it has a mandatory ordering after the group.)