What

This MR adds a websocket client to make JSONRPC requests and subscribe to events on an EVM node.

Depends on !16709 (merged).

Why

This is necessary to monitor logs emitted by the withdrawal contracts on Etherlink.

Manually testing the MR

Run the outbox monitor binary on an evm node which runs with websockets enabled and observe the head levels being printed on stderr.

./etherlink-outbox-monitor run --evm-node http://127.0.0.1:8545/ws

Edited Feb 18, 2025 by Alain Mebsout