Add unit tests for family inet

Change-Id: I1dda195c0e0a58b2cd3d0669c6ea2b919692ff6a
MPLS label rebake for multicast was done when label changes. However rebake should be done
whenever there is a change in component NH to which label points.
e.g. if interface gets added in interface comp NH mpls label was not getting updated with new comp NH
as it saw this operation as no-op bcoz there was no label change.

Code change fixes this scenario and rebakes label with comp NH everytime.
Old label is deleted only when label changes.

Change-Id: I18df452867e2f0890aae1800b20e61facd382e55
Merge "Add unit tests for family inet"
Merge "MPLS label rebake for multicast was done when label changes. However rebake should be done whenever there is a change in component NH to which label points. e.g. if interface gets added in interface comp NH mpls label was not getting updated with new comp NH as it saw this operation as no-op bcoz there was no label change."
Merge "Implement transit network functionality for service chaining"
Best path for service chain route must be BGP or XMPP

Change-Id: I5975f2f1e2031126c25eb624952c6d7a3a36434a
Closes-Bug: 1373744