message: [consensus] add counter for state sync notification
  Closes:
  Approved by: davidiw
diff: @@ -88,11 +88,12 @@ impl StateComputer for ExecutionProxy {
  .unwrap()
  .commit_blocks(block_ids, finality_proof)?
  );
  - if let Err(e) = self
  - .synchronizer
  + if let Err(e) = monitor!(
  + "notify_state_sync",
  + self.synchronizer
  .commit(committed_txns, reconfig_events)
  .await
  - {
  + ) {
  error!("failed to notify state synchronizer: {:?}", e);
  }
  Ok(())
  