introduce more tests for edge cases for view culling

Summary:
changelog: [internal]


# Why so many tests?
Differentiator has two modes: regular and reparenting. The reparenting one is almost a completely separate Differentiator, effectively doubling the complexity. It handles quite a few different special cases and is not covered by any reasonable tests, so here I am adding the tests to make sure every branch of the reparenting Differentiator is traversed.

Reviewed By: lenaic

Differential Revision: D73845746

Author: sammy-SC