Separate virtual nodes from the network definition

[jetuk]

There's also a random question of whether these "virtual" nodes should be defined somewhere separately in JSON. They are not part of the network really. You could imagine a format a bit like this:

{
  "network": {
    "nodes": [
       // ... all the network nodes
     ],
    "edges": [
       // ... and their connectivity
    ]
  },
  "virtual / groups / licences / constraints": [
    // Definition of all other non-network nodes
   ]
}

[jetuk]

It was also discussed to rename VirtualStorage to Licence for better alignment with user expectations.