Rather than iterating through all ports and leveraging the heavyweight
ml2 method, use a set of optimized functions that attempts to make bulk
port operations as speedy as possible.
The test test_bulk_ports_before_and_after_events_outside_of_txn is
deleted because with the change to using port OVO, the session will
not be closed, and it is not correct to check for it.
Change-Id: Ieea0e6074cd31a2d09ae92f1f3c8d375c6d8ecc2
Implements: blueprint speed-up-neutron-bulk-creation
2dc61dfbcc