Throttle scroll event in ScrollSnapper

[JayPanoz]

In hindsight after further testing we cannot rely on requestAnimationFrame to report scroll as it does not provide a consistent handling across devices – the delta may be impacted by refresh rate, etc.

This provides with an inconsistent experience in apps, depending on the device used, where reaching the delta can be very difficult, and hiding/showing elements on scroll takes multiple scrolls to reach a threshold for example.