Teach Control Node to handle change in VN index

Following changes are implemented:

- OriginVn is no longer stored in the primary XMPP route
- OriginVn is added to secondary routes during replication
- Change in VN index triggers notification of all routes in the RI
- Replicator updates the OriginVn for secondary routes
- Virtual Network for primary routes in a VRF is obtained from RI

Change-Id: I987431be6970ecba35485317648af2624b01ad53
Closes-Bug: 1382640
Merge "Teach Control Node to handle change in VN index"
Preserve SiteOfOrigin when creating ServiceChain routes

Following changes are implemented:

- Infra for SiteOfOrigin (aka RouteOrigin) community
- ServiceChain changes to preserve SiteOfOrigin from original route

Change-Id: I9b26ed7ef148a5e367db5deb226bcaeafad44db3
Partial-Bug: 1383721