[Feature Request] X² test for 2×2 contingency tables

[omaus]

Is your feature request related to a problem? Please describe. An often used variant of the X² (Chi-squared) test is that for 2×2 contingency tables (aka Cochran-Mantel-Haenszel test). Since the original X² test is already implemented, a version for 2×2 contingency tables can easily be implemented.

Describe the solution you'd like Implement it.

Describe alternatives you've considered Always write it yourself with the already existing X² test.

Additional context https://en.wikipedia.org/wiki/Cochran%E2%80%93Mantel%E2%80%93Haenszel_statistics (eng) https://de.wikipedia.org/wiki/Chi-Quadrat-Test#Vierfeldertest (ger)