fix: prevent shutdown timeout with promiseWithTimeout helper

fix: prevent shutdown timeout with promiseWithTimeout helper

Extract a shared promiseWithTimeout<T>() utility from 3 divergent
Promise.race+timeout implementations. Use it in ChargingStation.stop()
to cap stopMessageSequence at 30s so the stopped event is always
emitted even when the OCPP server is unreachable, preventing the
60s Bootstrap shutdown timeout.

Also fix mock server SecurityEventNotification handler parameter name
and add OCPP 2.0.1 E2E test plan.