Fixes to SouthBound REST

    - When a SFF is created/modified, we send to the REST URI founds in the
      SFF config ("rest-uri") instead of a generic URI
    - When a SFP is created/modified, we send only to the SFFs found in the
      service-hop list. For this we also use the rest-uri found in the SFF
      config

Change-Id: I8bd4905c6ededb9fb5003adaa00bca338673c8a1
Signed-off-by: Reinaldo Penno <rapenno@gmail.com>