Feature 10966 Prometheus recording rules for VNF and NS status

The new file ng-prometheus.yaml controls the deployment
of OSM Prometheus when using the new monitoring pipeline
architecture.

This file includes the recording rules necessary to obtain
VNF status and NS status, derived from VM status. Those rules
are stored in file `osm_rules.yml`, as part of configmap prom.

Change-Id: Ibc3aa25e741ef4e680e5775e1d52fa171af0813b
Signed-off-by: garciadeblas <gerardo.garciadeblas@telefonica.com>