Uncovered circle paths in PAGs

[adam2392]

Is your feature request related to a problem? Please describe.
The FCI algorithm R5 requires looking for uncovered circle paths, so we want a generic graph traversal function for circle paths.

Describe the solution you'd like
Implement pywhy-graphs function for uncovered circle paths that works on PAGs such that the FCI algorithm R5 can use it.

Describe alternatives you've considered
We may or may not refactor uncovered_pd_path.

Additional context
Original post: py-why/dodiscover#53 (comment)

cc: @jaron-lee