O2.1 Add instance metadata: We need a way to distinguish our current four long-term OnionPerf measurements that are automatically published to the Metrics portal from short-term experimental measurements.

In this task, we will add instance metadata to OnionPerf’s results in order to differentiate each experiment; we will store that data along with the actual measurement data in a separate, single archive. Without this task, we will be unable to distinguish the new experiments from the currently running OnionPerf instances, which makes the data collected unusable.