Add network templates for multiple NIC configuration

Add network templates for multiple NIC configuration

This change adds a set of network interface configurations for use
with network isolation. The multiple-nics templates includes one
separate NIC per network, and assumes that nic1 is used for the
provisioning network (ctlplane). Also included is an environment
file for including the multiple-nics configuration in a deployment.

This revision changes the ordering of the NICs. By doing that, it
is possible to wire up only a subset of the NICs for the storage
nodes, and it is possilbe to leave the External NIC only configured
on the controllers.

rdo: Updated this commit for static control plane configuration

Co-Authored-By: Rhys Oxenham <roxenham@redhat.com>
Change-Id: Ic878d1ed1a85b5705295d087a743570ca8213504