fix(array): toArray - convert to empty array only for nullish

[huynl-96]

Description

Based on the Nullable type of the argument, it looks like we only want to convert null and undefined into empty array. But in the current logic, falsy values (such as 0, false, '', etc.) are also being converted. It is probably better to respect these values.

If there is a good reason to bypass the falsy values, please feel free to close this PR.

Linked Issues

NA

Additional context

I think we should take advantage of it.each for looping through test cases

• input and expected (output) of test cases are grouped in the same format [input, expected]
• Avoid code repetition for the test implementation.

I have added test cases for toArray function as the demo

[antfu]

Nice catch!