message: Output ping/pong times and invalid pong count in network insights
diff: @@ -179,13 +179,15 @@ impl OutgoingStateInsight {
  } => {
  let rtt_ms = rtt.map(|duration| duration.as_millis());
  - // TODO: Display last ping/pong and invalid pong count in a concise, but meaningful manner.
  write!(
  f,
  - "connected -> {} @ {} (rtt {})",
  + "connected -> {} @ {} (rtt {}, invalid {}, last ping/pong {}/{})",
  peer_id,
  peer_addr,
  - OptDisplay::new(rtt_ms, "?")
  + OptDisplay::new(rtt_ms, "?"),
  + invalid_pong_count,
  + OptDisplay::new(last_ping_sent.map(|t| time_delta(now, t)), "-"),
  + OptDisplay::new(last_pong_received.map(|t| time_delta(now, t)), "-"),
  )
  }
  OutgoingStateInsight::Blocked {
  