Most of this code comes from an old PR that @fruitcoder put up TextureGroup#795 2 years ago.

When creating our array of accessibilityElements, we need to respect the value of `accessibilityElementsHidden`. If the value of this property changes, we need to invalidate the cached accessibility elements (unless we are in the experiment that doesn’t cache `accessibilityElements`).

I created a simple test app and made sure this matched UIKit’s implementation. I also added a test case that changes the value of `accessibilityElementsHidden` and makes sure the proper accessibilityElements are returned.

Talked with huy and decided to make a method to check if a  node is hidden, transparent or has `accessibilityElementsHidden` set to yes. Use this in 2 places when collecting accessibility elements to early exit or filter nodes.