Issue #3311480 by pdureau, Grimreaper, DuaelFr: Reduce preprocess hooks usage...
requested to merge issue/ui_patterns-3435827:ui_patterns-3414363-3414363-2.0.0-alpha1-form-builder-context-selector into 2.0.x
Issue #3311480 by pdureau, Grimreaper, DuaelFr: Reduce preprocess hooks usage by adding add_class() & set_attributes() filters