message: Add logs to `linear_chain_sync`.
diff: @@ -134,6 +134,7 @@ where
  Effects::new()
  }
  Some(init_hash) => {
  + trace!(?init_hash, "Start synchronization");
  // Start synchronization.
  effect_builder.fetch_block(init_hash, init_peer).option(
  move |value| Event::GetBlockResult(init_hash, Some(value)),
  @@ -222,6 +223,7 @@ where
  self.fetch_next_block_deploys(effect_builder, rng)
  }
  Event::NewPeerConnected(peer_id) => {
  + trace!(%peer_id, "New peer connected");
  let mut effects = Effects::new();
  if self.peers.is_empty() {
  // First peer connected, start dowloading.
  