Metadata: extend for system information about the node
Include MID and HWPID items if present in IqrfDb into metadata structure present here: https://apidocs.iqrf.org/iqrf-gateway-daemon/v230/json/iqrf/examples/iqrfSensor_Frc-response-1-0-0-example.json
It can be discussed further if metadata is right place to include these items.