Event-driven streaming of sensor data for MPLS LSP record route objects

ON_CHANGE notification for streaming MPLS label-switched path (LSP) record route object statistics. Using ON_CHANGE mode, data values are not streamed but sent only when data values change. Support includes leaf nodes under the resource path /network-instances/network-instance/mpls/signalingprotocols/ rsvp-te/sessions/session/record-route-objects/record-route-object/state/.