Add SIGQUIT signal handler to match SIGINT behavior

Why it matters

This feature ensures that ClickHouse processes respond consistently to both SIGINT and SIGQUIT signals by performing a graceful shutdown. It improves process management and shutdown reliability, providing users with an additional reliable way to interrupt and terminate ClickHouse safely.

How to use it

Users can send a SIGQUIT signal to the ClickHouse server process (e.g., using kill -QUIT <pid>) to trigger a graceful shutdown, just like with SIGINT.