Prior to routed networks we only had one subnet per network.
With routed networks each network can have multiple subnets.
The NetCidrMapValue should contain a list storing the cidr
of each subnet for each network.
Ceph:
list_join is used to make a comma separated list of
cidrs for public_network, monitor_address_block,
cluster_network and radosgw_address_block.
Partial: blueprint tripleo-routed-networks-templates
Depends-On: Ia8e219b30d4f8b199b882e95fe2834252a92c15a
Depends-On: I1ace0a02e6aa2610559fee0d8576e6f1bc98d699
Change-Id: I68e064d23ec5d43f59146d974cae604d2c5fdb52