metrics: add more monitor metrics for EVN;

[galaio]

Description

This PR adds more monitor metrics for EVN, it can be used for monitor the network improvement from EVM.

Example

1. Monitor new block fetching feature:

# legacy block fetching cost time
eth_fetcher_block_legacy_cost{job=~"$jobs",quantile=~"$percentile"}
# new block fetching cost time
eth_fetcher_block_quick_cost{job=~"$jobs",quantile=~"$percentile"}
# new block fetching success rate
eth_fetcher_block_quick_success{job=~"$jobs"}/(eth_fetcher_block_quick_success{job=~"$jobs"}+eth_fetcher_block_quick_err{job=~"$jobs"})
# new block fetching fallback rate
eth_fetcher_block_quick_fallback{job=~"$jobs"}/(eth_fetcher_block_quick_success{job=~"$jobs"}+eth_fetcher_block_quick_err{job=~"$jobs"})

2. EVN Peer Monitor

# total peers
p2p_peers{job=~"$jobs"}
# even proxyed peers
evn_peer_proxed{job=~"$jobs"}
# even onchainValidator peers
evn_peer_ onchainValidator{job=~"$jobs"}
# even whiteList peers
evn_peer_ whiteList{job=~"$jobs"}

You can also query the peers RPC to get the detailed EVN feature flags for a peer.

./bsc attach --exec "admin.peers" ./geth.ipc

Changes

Notable changes:

• metrics: add evn peer monitor metrics;
• metrics: add block fetching timer, success rate;
• chore: opt some broadcast logs;

[Copilot]

Pull Request Overview

This PR enhances monitoring for EVN by introducing new metrics for peer flags and block fetching performance.

• Added new EVN flag fields in the PeerInfo structure (p2p/peer.go).
• Introduced new metrics in eth/peerset.go to track proxied, whitelist, and on-chain validator peers.
• Instrumented block fetching performance metrics and improved logging for EVN peers in eth/handler.go and eth/fetcher/block_fetcher.go.

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
p2p/peer.go	Added new EVN flag fields to PeerInfo for monitoring purposes.
eth/peerset.go	Registered new gauges for EVN peer metrics and updated feature counts.
eth/handler.go	Enhanced debug logging to include EVN flag status during broadcasts.
eth/fetcher/block_fetcher.go	Added timers and meters to track block fetching costs and outcomes.

Comments suppressed due to low confidence (4)

p2p/peer.go:591

• [nitpick] Consider renaming 'ProxyedValidatorFlag' to 'ProxiedValidatorFlag' for clarity and consistency.

ProxyedValidatorFlag bool                   `json:"proxyedValidatorFlag"`

eth/peerset.go:75

• [nitpick] Consider renaming 'evnProxedPeerGuage' to 'evnProxiedPeerGauge' to correct the spelling and improve consistency.

evnProxedPeerGuage           = metrics.NewRegisteredGauge("evn/peer/proxed", nil)

eth/peerset.go:76

• [nitpick] Consider renaming 'evnWhiteListPeerGuage' to 'evnWhitelistPeerGauge' to fix the spelling of 'Gauge' and standardize naming.

evnWhiteListPeerGuage        = metrics.NewRegisteredGauge("evn/peer/whiteList", nil)

eth/peerset.go:77

• [nitpick] Consider renaming 'evnOnchainValidatorPeerGuage' to 'evnOnchainValidatorPeerGauge' to correct the spelling of 'Gauge'.

evnOnchainValidatorPeerGuage = metrics.NewRegisteredGauge("evn/peer/onchainValidator", nil)