[Feature] cor_sort() can deal with non-square matrices

[DominiqueMakowski]

cor_sort() should be able to deal with non square matrices (whenever we correlate two different dataframes).

Currently the method is implemented only for raw R matrices.

Todo:

• Improve tests: make sure it works with most outputs classes of correlation()
  • cor_sort(correlation::correlation())
  • cor_sort(summary(correlation()))
  • cor_sort(as.matrix(correlation()))
  • ...
• Make it so that it works with outputs from the correlation() and summary(correlation()).

[strengejacke]

fixed some lintrs and especially some issues with the print() methods, which were actually far beyond and out of scope of this PR, but anyway... Not sure about the exact machinery of the function, but looking at the code and the test you added, looks good to me!

[strengejacke]

Not sure why the local test creates a different markdown snapshot than what is expected here on GitHub actions, but we can address that later.