`Option::fromArraysValue` should have parameter `$key` typed as `int|string` (and possibly `null|int|string`)

[niconoe-]

When looking at the current version (1.9.2), the PHPDoc of Option::fromArraysValue tells that parameter $key must be a string, while it could also be an int, in case we want to use Option::fromArraysValue with an indexed array rather than an associative one.

This would also make sense regarding the PHPDoc of the $array parameter of the exact same method.

If I may, I would like to go further and allow null for $key too, which would automatically leads to returning a None instance.

Let's have this:

$fooEntitites; // array<int, Entity>
$barEntity->foo_id; // int|null

// $barEntity->foo_id can be:
// - `null` if this Bar isn't bound to any Foo
// - `int` but not an existing key in $fooEntities for some reasons
// - `int` and existing key in $fooEntities

$foo = Option::fromArraysValue($fooEntities, $barEntity->foo_id)->getOrElse(null);

This last line is currently forbidden to me by PHPStan/Psalm because of the typehint not being aligned with your current version of your library.

I will try to provide a PR if you're interested in.

Thanks a lot!