Improve filter_* array handling, support FILTER_REQUIRE_ARRAY

[herndlm]

Refs: phpstan/phpstan#9134

fyi @GMQS

See https://www.php.net/manual/en/filter.filters.flags.php and https://3v4l.org/p8jA9 and

Support for more specialised arrays like constant arrays or lists as inputs could be improved still, but this is already complicated enough and I'm not sure if it's worth it. Could be added later still I suppose.

[herndlm]

I assume you're busy with other things, but since it's in the same scope - support for filter_input() is still open via #2010 and should be ready :)

[ondrejmirtes]

Thank you!