Sidecar: Telemetry & Metrics

[merklefruit]

### Bolt-sidecar telemetry
- [ ] Review the level of existing traces, and change or remove any unnecessary ones
- [ ] Add the option to instrument a Prometheus listener to collect useful metrics
- [ ] Add meaningful metrics to the sidecar, including health-checks, alerts, and important events
- [ ] Infra: create a default Grafana dashboard to visualize the sidecar status
- [ ] (optional) Add the option to instrument a log collector such as a remote Loki instance
- [ ] (optional) Add the option to log to a file in JSON to support external log collectors like Promtail

[thedevbirb]

I'd love to take this, since I'm quite unfamiliar with these tools and it'd be a great way to learn them