feat: spam rpc

[0xl3on]

Motivation

Hey guys, pretty big feature so sorry for the big PR:

Closes #462

Each RPC method is strongly typed clap subcommand, as mentioned in the issue. eth_sendRawTransaction is excluded because nonce is baked into the signed payload so spamming would fail.

Solution

Changes from existing code:

• Moved inner logic from collect_latency_metrics at test_scenario.rs to a shared function at bucket.rs so we can re-use across tx and rpc spam
• Extended the gen html logic to also support rpc spam specific metrics

New code

• Added rpc command
• New rpc.rs module with the spam logic

PR Checklist

• Added Tests
• Added Documentation
• Ran cargo +nightly clippy --workspace --lib --examples --tests --benches --all-features --locked --fix
• Ran cargo fmt --all
• Note breaking changes in PR description, if applicable
• update changelogs
  • Update CHANGELOG.md in each affected crate
  • add a high-level description in the root changelog

[zeroXbrock]

thanks @0xl3on -- should be able to review tomorrow!