Tests that multiple sessions cannot trace simultaneously.
Starting tracing in session1
{
    id : <number>
    result : {
    }
    sessionId : <string>
}
Starting tracing in session2
{
    error : {
        code : -32000
        message : Tracing has already been started (possibly in another tab).
    }
    id : <number>
    sessionId : <string>
}
Stopping tracing in session1
{
    id : <number>
    result : {
    }
    sessionId : <string>
}
Stopping tracing in session2
{
    error : {
        code : -32000
        message : Tracing is not started
    }
    id : <number>
    sessionId : <string>
}
session1: dataCollected=true tracingComplete=true
session2: dataCollected=false tracingComplete=false