message: [mempool] Log number of transactions returned to consensus
  Closes:
  Approved by: phoenix-antigravity
diff: @@ -171,6 +171,7 @@ impl Mempool {
  /// `batch_size` - size of requested block
  /// `seen_txns` - transactions that were sent to Consensus but were not committed yet
  /// Mempool should filter out such transactions
  + #[allow(clippy::explicit_counter_loop)]
  pub(crate) fn get_block(
  &mut self,
  batch_size: u64,
  @@ -184,9 +185,11 @@ impl Mempool {
  // but can't be executed before first txn. Once observed, such txn will be saved in
  // `skipped` DS and rechecked once it's ancestor becomes available
  let mut skipped = HashSet::new();
  -
  + let seen_size = seen.len();
  + let mut txn_walked = 0usize;
  // iterate over the queue of transactions based on gas price
  'main: for txn in self.transactions.iter_queue() {
  + txn_walked += 1;
  if seen.contains(&TxnPointer::from(txn)) {
  continue;
  }
  @@ -218,11 +221,14 @@ impl Mempool {
  skipped.insert(TxnPointer::from(txn));
  }
  }
  + let result_size = result.len();
  // convert transaction pointers to real values
  let block: Vec<_> = result
  .into_iter()
  .filter_map(|(address, seq)| self.transactions.get(&address, seq))
  .collect();
  + debug!("mempool::get_block: seen_consensus={}, walked={}, seen_after={}, result_size={}, block_size={}",
  + seen_size, txn_walked, seen.len(), result_size, block.len());
  for transaction in &block {
  self.log_latency(
  transaction.sender(),
  