While we might never be able to have 100% of our code strict, we can at
the very least do it for all of our tests. This ensures that our tests
are using our API with the types as intended by the test author, and not
silently be cast to what our API requires.
* Use validation classes rather than traits for Statistical functions, and some verification of nullable arguments
* Eliminate more of the issues resolved in phpstan baseline
* Additional unit tests and rationalisation for Financial Functions
* Providing a series of sample files for Financial functions
* Refactor the last of the existing Financial functions
* Some more unit tests with default assignments from null arguments
Co-authored-by: Adrien Crivelli <adrien.crivelli@gmail.com>
* Extract Normal and Standard Normal Distributions from the Statistical Class
* Extract ZTest from the Statistical Class, and move it to the Standard Normal Distribution class
Additional unit tests for NORMINV()
* Extract LogNormal distribution functions from Statistical