Could still be broken. Attempts to fix the citation sync without causing a dirty state that prevents uploading to pypi

Refactors init of the figure class to reduce cognitive load and improve readability by splitting the logic into helpers.

Marked this PR as ready for a refactor down the line to make figure more behave as an interface rather than wearing too many hats(functions).

Replace m2r2 to a pure html renderer + wire in unittest to prevent this from happening again.

The new ultraplot/tests/test_docs_fetch_releases.py loads
docs/_scripts/fetch_releases.py via importlib, which imports `requests`
at module level. The conda env used in CI didn't include it, causing
all eight tests to fail with ModuleNotFoundError.

* Implement fix for 689