Changes to List end users for the organization (optionally filter by org_external_end_user_id)

added the optional property items/items/dropped_external_ids to the response with the 200 status

added the optional property retry_after to the response with the 400 status

added the optional property retry_after to the response with the 401 status

added the optional property retryable to the response with the 400 status

added the optional property retryable to the response with the 401 status