Too many fields required to render a node

[kd-ods]

Bug description

In the spec we say that the minimum fields required to render an entity node are:

• recordType is “entity”
• if recordStatus exists, it is not “closed”

And the equivalent for person nodes.

But in the demo, more fields than this have to be included.

Steps to reproduce

1. Paste the following into the tool and click 'Draw'

[
  {
    "statementDate": "2019-01-20",
    "recordType": "entity",
    "recordDetails": {
      "entityType": {}
    }
  }
]

2. Notice that an unknown entity node is rendered.

3. Remove any one of the fields and try to redraw .

For person nodes, this is currently the minimal json that renders a node:

[
  {
    "statementDate": "2019-01-20",
    "recordType": "person"
  }
]

Expected behaviour

Ideally the following should render a node:

[
  {
    "recordType": "entity"
  }
]

And the equivalent for "person".

If making that work causes too many knock-on problems at this stage, we can change the spec.