Probe services should carry all information in JSON body

[azaroth42]

We are currently mixing layers between HTTP and the response payload. The client needs access to the status code (200 vs 4xx (vs 3xx?)) but also information from the body. We should limit to only one layer and just put everything in the JSON body. While this might not be appreciated by purists, it is much easier for implementers and they are our primary audience.

eg.

{
 "id": ...
 "type": "AuthProbeService2",
  "status": "success",
  "for": {...}
}

[ktamaral]

The latest version of the IIIF Authorization Flow 2.0 probe service has a property called status that has the value of the status that the service returned. This issue can be closed.