This patch will do 2 things:
1. Add 'vnf_ids' and 'vnffg_ids' fields as outputs from network
service list command. Users can know which VNFs or VNFFG, that
belongs to specific NS.
2. Add 'ns_id' fields to VNFFG list command, that shows which
network service the current VNFFG belongs to it.
Partially-implements: blueprint vnffg-ns
Change-Id: If6c5550f94e676fb2062e32ddc069acd5dfb6490