Support `scrollend` event

We should implement the `scrollend` events which fires when a page has finished scrolling.

> The scrollend event fires when:
> - The browser is no longer animating or translating scroll.
> - The user's touch has been released
> - The user's pointer has released the scroll thumb.
> - The user's keypress has been released
> - Scroll to fragment has completed
> - Scroll snap has completed
> - scrollTo() has completed
> - The user has scrolled the visual viewport.

> The scrollend event does not fire when:
> - A user's gesture did not result in any scroll positional changes (no translation occurred).
> - scrollTo() did not result in any translation.

https://developer.chrome.com/blog/scrollend-a-new-javascript-event#event_details