feat: Metrics

[nuts-rice]

Hi y'all I'm currently working on metrics for an etherum load balancer Figured since you're doing lots of RPC calls and db queries it might be nice to point towards some resources like https://docs.rs/prometheus/latest/prometheus/ and https://docs.rs/prometheus-metric-storage/latest/prometheus_metric_storage/ I also found reth's metrics crate as a good example of building metrics this could be built as a oneshot channel-typed sender and reciever deal as well using tokio's sync module

[joshstevens19]

Great idea fancy doing it @nuts-rice ?