Create Testing Environment

[Howquez]

1. Create an exact copy of the app and deploy it separately (with fewer resources)
2. Create a testing functionality in the configurator: Clicking on it should direct the users to the copied app and potentially hide the prolific input field. Also fix the max amount of participants to 20 or so.

The underlying idea is that we have two databases: one with testing sessions, which can be deleted frequently and one with actual experimental data which is tidied up rather slowly.