GENIUS-130: OF Tunnels support For ITM Direct Tunnels (of-tunnels)

GENIUS-130: OF Tunnels support For ITM Direct Tunnels (of-tunnels)

Genius already supports creation of OF-tunnels through interface-manager.
With itm-direct-tunnels, interface-manager is by-passed for all
internal tunnel operations, and in such scenarios, OF tunnels are
not currently supported. This feature adds support for flow based
tunnels on top of itm-direct-tunnels for better scalability.

Specification Gerrit : https://git.opendaylight.org/gerrit/#/c/71659/

Gerrits Topic : https://git.opendaylight.org/gerrit/#/q/topic:of-tunnels+(status:open+OR+status:merged)

Change-Id: I32c9f1796b86670263574748bb937d9f18869b58
Signed-off-by: Karthika Panneer <r.p.karthika@ericsson.com>