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.
Implement Array-enabled for ERROR.TYPE() function
Extract ERROR.TYPE() function tests into separate test file
Extract error function tests into separate test files
And thus complete the implemented Information functions
* First steps toward array-enabling the information functions
Also includes moving unit tests out from Functions and into a separate, dedicated Information folder
* Resolve issue with IF(), branch pruning and calculation cache (ensure that we don't convert the if condition to a bool before we've tested to see if it evaluates to an error)
More refactoring