Fix#64 (really!), closed as stale in December 2017, another in our "better late than never" series. Excel's INDEX function doesn't really behave quite as described. If a single row is used as an argument, either in literal form `{item1, item2, item3}` or expressed as a range `A1:A6`, INDEX is happy to evaluate the array as if each entry were a row rather than a single item. PhpSpreadsheet is changed to do likewise.
INDEX also returned `#REF!` when it would normally return an array (which would often be reduced to its leftmost topmost entry later). This code is deleted, invalidating one existing test, and INDEX will now operate like other functions which can return arrays.
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.
Scrutinizer had previously suggested annotations for 3 LookupRef tests, but it no longer accepts its own annotation for those cases. This PR cleans them up. ColumnsTest and RowsTest are extremely straightforward.
IndexTest is a bit more complicated, but only because, unlike the other two, it had no test which executed in the context of a spreadsheet. And, when I added those, I discovered a couple of bugs. INDEX always requires at least 2 parameters (row# is always required), but its entry in the function table specified 1-4 parameters, now changed to 2-4. And, omitting col# is not handled the same way as specifying 0 for col#, though the code had treated them identically. (The same would have been true for row# but, because it is now required, ...)