[FEAT] Statistics for relations between two `NadaArray`s

[manel1874]

Request new nada-numpy feature

Implement the following statistical functionalities for relations between two NadaArrays, modelled after the Python statistics module:

• Correlation
• Covariance
• Linear regression

Description

The new features should be integrated into the nada-numpy library and should operate on two NadaArray objects. The functionalities should be defined as follows:

• Correlation: Calculate and return Pearson's correlation coefficient between two NadaArray objects.
• Covariance: Compute and return the sample covariance between two NadaArray objects.
• Linear Regression: Perform a simple linear regression on the two NadaArray objects and return a tuple (slope, intercept) representing the best-fit line.

Each function should take two NadaArray objects as input and output the respective statistical measure.

Reference material

• Python statistics