restapi: Add "permissions" sub-collections to vnic profiles

The "permissions" sub-collections is added to vnic profiles
under the networks top collection:

api/networks/{network:id}/vnicprofiles
api/networks/{network:id}/vnicprofiles/{profile:id}/permissions
api/networks/{network:id}/vnicprofiles/{profile:id}/permissions/{permission:id}

Change-Id: I02573ec87a40c7e017a24f334083044b051613ac
Bug-Url: https://bugzilla.redhat.com/1014985
Signed-off-by: Moti Asayag <masayag@redhat.com>