[virtual] PDF-based network defs for cluster nodes

[virtual] PDF-based network defs for cluster nodes

Decouple virtual cluster nodes (ctl, gtw etc.) from opnfv_fn_* vars
in favor of parsing PDF/IDF.
This is the first step towards unifying baremetal and virtual network
definition templates, as well as allowing virtual nodes to run on a
remote hypervisor (and eventually with a different arch).

opnfv_fn_* vars will still be used for infra VMs spawned on FN (cfg01
and optionally mas01).

Adopt new 'net_map.j2' from Pharos submodule for new templates (virt),
as well as old ones (baremetal).

JIRA: FUEL-322

Change-Id: I150c2416566bbe42ea11cd00f12a8a7bf96776c2
Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>