Changes to Send sample event data to a Destination within a Pack

added the media type application/json for the response with the status 401

added the optional property details to the response with the 500 status

the response property count became required for the status 200

the response property items became required for the status 200

the response property message became required for the status 500

added the required property status to the response with the 500 status

added the non-success response with the status 400

endpoint added