DB: Track how exactly the repeated measures testing is done

[bastianilso]

If we run the same participant through several eye tracking accuracy trials, we need to be able to distinguish between several scenarios:

1. We let the cameras calibrate to the participant once, but run the accuracy test several times (This is what is done in Jan2020 experiment I think @YoNeXia ?)
2. We calibrate the cameras each time we run the participant through the accuracy test.
3. We unmount the VR headset and mount it again, each time we run the participant through the experiment.