kstyle: Make CheckBox and RadioButton animation work with Qt Quick Controls
kstyle: Register Qt Quick Controls with animations
Since it's all software-rendered and indirect, only the CheckBox and RadioButton controls are actually wired up since the rest of the animations is quite subtle.
kstyle: Use styleObject for widgetStateEngine in CheckBox/RadioButton
Prepares it for doing the animation also with Qt Quick Controls without an actual QWidget.
kstyle/animations: Use QObject as base type rather than QWidget
This prepares for the animation engine being used with Qt Quick Controls.
In most cases the type is cast to the relevant widget type for checking anyway, so might as well use the cast object further down but not require a QWidget at the beginning.
Animation speed slowed to 2000 ms for demonstration
Radio button animation fix so it doesn’t shrink and grow again is !544 (merged)