Network: reduce memory retained by closed or failed libp2p RPC streams. Nodes now release queued stream data when a stream is lost or when an RPC stream finishes, and expose new logs and Prometheus metrics to help operators identify stream queue buildup by protocol. Queue buildup logging can be tuned with `MINA_LIBP2P_STREAM_QUEUE_LOG_THRESHOLD_MESSAGES`, `MINA_LIBP2P_STREAM_QUEUE_LOG_THRESHOLD_BYTES`, `MINA_LIBP2P_STREAM_QUEUE_LOG_SUMMARY_INTERVAL_MINUTES`, and `MINA_LIBP2P_STREAM_QUEUE_GROWTH_FACTOR`.
