ScrollToPageEvent Class
Useful for doing animations after a page was found and selected.
If buttons are used for navigation, this event occurs on Prev/Next button tap.
If scrolling with FAScrollSnapBehaviour.snapToFirst set to true, this occurs as soon as the dragging end.
If scrolling with FAScrollSnapBehaviour.snapToFirst set to false, this occurs after the scroll speed is slowed enough so it locks to a page.