[W-13547158] Empty any of list

[carowright]

Bug: When defining a schema with a property as a list of anyOf options, we were not showing the options available

e.g.

Patient:
      type: object
      description: The Patient resource exposed by the NHI.
      properties:
        extension-anyOf:
          type: array
          items:
            anyOf:
              - $ref: '#/components/schemas/Extension1'
              - $ref: '#/components/schemas/Extension2'
              - $ref: '#/components/schemas/Extension3'

Fix: correctly read amf model, this information is stored under or key