fix: align ConnectionTimeOut semantics with OCPP spec

fix: align ConnectionTimeOut semantics with OCPP spec

ConnectionTimeOut/EVConnectionTimeOut is the EV cable insertion timeout
per OCPP 1.6 §9.1.6 and OCPP 2.0.1 TxCtrlr spec, not a WebSocket
timeout. Split DEFAULT_CONNECTION_TIMEOUT into three purpose-specific
constants:
- DEFAULT_EV_CONNECTION_TIMEOUT (180s): OCPP cable insertion timeout
- DEFAULT_WS_HANDSHAKE_TIMEOUT (30s): WebSocket handshake timeout
- DEFAULT_WS_RECONNECT_DELAY (30s): WebSocket reconnection delay
- DEFAULT_MESSAGE_TIMEOUT (30s): OCPP 2.0 MessageTimeout default

Dissociate WebSocket handshake/reconnect from OCPP ConnectionTimeOut
configuration. Initialize ConnectionTimeOut with 180s per spec.