requestAnimationFrame callback should have type `Timestamp -> Effect Unit`

[PanAeon]

According to mdn requestAnimationFrame's callback function:

The callback function is passed one single argument, a DOMHighResTimeStamp similar to the one returned by performance.now(), indicating the point in time when requestAnimationFrame() starts to execute callback functions.

[PanAeon]

@garyb , I can send pull request, but I'm not sure how to correctly represent DOMHighResTimeStamp