message: Add error object to rdkafka checkpoint_error event
diff: @@ -307,7 +307,7 @@ export class RdkafkaConsumer extends RdkafkaBase implements IConsumer {
  && hasPartition;
  const latency = Date.now() - startTime;
  - this.emit("checkpoint_error", partitionId, queuedMessage, retries, latency, willRetry);
  + this.emit("checkpoint_error", partitionId, queuedMessage, retries, latency, willRetry, ex);
  if (willRetry) {
  return this.commitCheckpoint(partitionId, queuedMessage, retries + 1);
  