if the user has interacted with the sound check, they dont need the tutorial mode to turn on fixes
https://github.com/ProjetDeRechercheSurLecriture/DyslexDisorthGame/issues/183
white class was undeclared
selecting a participant sets the participant for the experiment

fixes https://github.com/ProjetDeRechercheSurLecriture/DyslexDisorthGame/issues/174
hide text instructions if in child mode

fixes https://github.com/ProjetDeRechercheSurLecriture/DyslexDisorthGame/issues/147