restapi: Add labels to network and host_nic

(cherry picked from commit ff1735a66c561c249148ed71b7ce6ad17cff7a57)

Change-Id: I36f3833b8eb3878c5eac996f7c9b38d4ae8a683a
Bug-Url: https://bugzilla.redhat.com/1084937
Bug-Url: https://bugzilla.redhat.com/1085736
Signed-off-by: Yevgeny Zaspitsky <yzaspits@redhat.com>