ConnectionId
- Exposes the `ConnectionId` in the various `SwarmEvent` variants. - Tracks connection duration in `libp2p-metrics::swarm`. Pull-Request: #3927.
Implementation of the libp2p perf protocol according to https://github.com/libp2p/specs/pull/478/. //CC @MarcoPolo as the author of the specification. **Don't (yet) expect this to produce reliable performance metrics.** Pull-Request: #3508.