Changes to Deliver a steering message to a running task

added the new chat enum value to the request property source

added the media type application/json for the response with the status 200

added the media type application/json for the response with the status 400

added the media type application/json for the response with the status 403

added the media type application/json for the response with the status 404

added the media type application/json for the response with the status 422

endpoint added