feat(anvil): add optional verbose rpc payload logging

[aodhgan]

Motivation

Often times when testing client integrations I wish to quickly debug what successful RPC calls (and their params) are made. To get around this I typically resort to setting up a Man In the Middle style proxy to simply log the requests and responses, but this is a nuisance.

Solution

This PR introduces a backward compatible optional --rpc-log flag which, when enabled provides verbose logging of the form:

RPC request [id=10390, method=eth_maxPriorityFeePerGas, peer=127.0.0.1:58496, ts=2025-12-18T01:14:59.489792+00:00]: {"jsonrpc":"2.0","method":"eth_maxPriorityFeePerGas","params":null,"id":10390}
RPC response [id=10390, method=eth_maxPriorityFeePerGas, peer=127.0.0.1:58496, ts=2025-12-18T01:14:59.489792+00:00]: {"result":"0x3b9aca00"}

Specific code changes:

• Added a --rpc-log CLI flag that feeds into NodeConfig, persists the RPC payload logging preference, and exposes a with_rpc_logging builder to propagate the setting
• Introduced an RpcCallLogContext (id, method, peer address, timestamp) and a centralized log_rpc_method helper so method banners are suppressed when payload logging is enabled while request/response payloads continue to include contextual metadata
• Wrapped HTTP RPC handling to capture raw JSON, attach the logging context (including peer/timestamp), and pass everything through to EthApi::execute_with_raw; Otterscan handlers now reuse the shared method-logging helper.

PR Checklist

• Added Tests
• Added Documentation
• Breaking changes

This PR used ChatGPT's copilot for implementation.