Move setup_instance_group to conductor

During prework of scheduler split, we identified that
there is a call from setup_instance_group to the Nova object
InstanceGroup. That prevents the scheduler to be split as a
separate project because it would have an external dependency to
a Nova object.
The implementation here is providing the call by the conductor
before the call to select_destinations as this method only
modifies filter_properties for adding group details.

Co-Authored-By: Ed Leafe <ed@leafe.com>

Change-Id: Ib6556c8f6d6e6dcdb65a0bdb1894c66e92b35230
Merge "Move setup_instance_group to conductor"