Introduce TBFPC and TBF_FCI causal discovery algorithms (#1947)

* Introduce TBFPC and TBF_FCI causal discovery algorithms

Introduces the TBFPC (Target-first Bayes Factor PC) and TBF_FCI (Target-first Bayes Factor Temporal PC) classes for causal discovery using Bayes factor conditional independence tests. Includes comprehensive docstrings, public APIs, and extensive tests for both algorithms, covering edge rules, forbidden edges, time series support, and error handling.

* Interesting jeje

* Update causal.py

* Run pre-commit fixes

* Update causal.py

* Document TBF_FCI public API

* Document internal TBF_FCI helpers

* Update causal.py

Author: cetagostini