[scala] result code: use exceptions internally

processRequestWithException.scala

def processRequestWithException(userId: UUID, requestId: UUID): BusinessResult = {
  case class BusinessException(result: BusinessResult) extends RuntimeException

  try {
    val user = getUser(userId).getOrElse(throw new BusinessException(BusinessResult.UserNotFound))
    val request = getRequestById(requestId).getOrElse(throw new BusinessException(BusinessResult.RequestNotFound))
    checkAccess(request, user).toOption.getOrElse(throw new BusinessException(BusinessResult.NotOwner))
    BusinessResult.Ok
  } catch {
    case be: BusinessException => be.result
  }
}