Issue #3382510 by phenaproxima, Wim Leers, alexpott, longwave,...
Issue #3382510 by phenaproxima, Wim Leers, alexpott, longwave, claudiu.cristea, borisson_, lauriii, effulgentsia, bircher: Introduce a new #config_target Form API property to make it super simple to use validation constraints on simple config forms, and adopt it in several core config forms