test_client: Parse incoming message to determine type
test_client: Parse incoming message to determine type

Don't rely on the JSON string being formatted in a certain way

pererikb/openwebrtc,multipath-rtp/openwebrtc,multipath-rtp/openwebrtc,shoreflyer/openwebrtc,philn/openwebrtc,pererikb/openwebrtc,multipath-rtp/openwebrtc,EricssonResearch/openwebrtc,EricssonResearch/openwebrtc,shoreflyer/openwebrtc,EricssonResearch/openwebrtc,shoreflyer/openwebrtc,shoreflyer/openwebrtc,EricssonResearch/openwebrtc,shoreflyer/openwebrtc,multipath-rtp/openwebrtc,philn/openwebrtc,philn/openwebrtc,philn/openwebrtc,pererikb/openwebrtc,pererikb/openwebrtc,pererikb/openwebrtc,shoreflyer/openwebrtc,pererikb/openwebrtc,multipath-rtp/openwebrtc,EricssonResearch/openwebrtc,philn/openwebrtc,shoreflyer/openwebrtc,pererikb/openwebrtc,EricssonResearch/openwebrtc,philn/openwebrtc,philn/openwebrtc,multipath-rtp/openwebrtc,multipath-rtp/openwebrtc,EricssonResearch/openwebrtc