OVSDB-445 Port creation not reflected in OperDS

OVSDB-445 Port creation not reflected in OperDS

When a port is deleted and added in same ovs-vsctl command
it doesn't show up in OperDS. This is because
OvsdbOperationalCommandAggregator always processes removes
after Updates. Since delete is being done for same port right
after update, it ends up not adding it to datastore.

Fix is to check if same port is present in updates or not
before deleting it.

Note: This may impact other such configuration too, though
not sure of any valid use cases for bridges etc.

Change-Id: I596ceaf579c4342a3e6bc282ce140cf15a295d60
Signed-off-by: Vishal Thapar <vishal.thapar@ericsson.com>