Add Intersection Observer E2E tests for FB (#55656)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/55656

Changelog: [Internal] - Update IO examples for easier E2E testing

Meta:
Updated approach to render IntersectionObserver examples for E2E testing.

Updated some of the examples to be friendlier for e2e assertions

Reviewed By: rubennorte

Differential Revision: D92897290

fbshipit-source-id: 1ee827036951798495a7e5840fd60d2b18877e64