Obtener estado de una sesión específica

{
    "success": true,
    "session": {
        "sessionId": "string",
        "status": "initializing",
        "phoneNumber": "string",
        "qrCode": "string",
        "lastActivity": "2019-08-24T14:15:22Z",
        "connectionInfo": {
            "connectedAt": "2019-08-24T14:15:22Z",
            "reconnectCount": 0,
            "lastError": "string"
        },
        "metadata": {},
        "statistics": {
            "messagesSent": 0,
            "messagesReceived": 0,
            "activeChats": 0
        }
    }
}