Support a state change handler for all control props
In our simple situation, having an
onToggleChange handler is sufficient because the
on state is the only state we have, but in a more complex component, there could be many items of state. We could make an prop callback for each of those items of state, but that could drastically increase the complexity and repetition of our component. Instead, let's make an
onStateChange that's called when any state changes.