fs: readdir optionally returning type information

readdir and readdirSync now have a "withFileTypes" option, which, when
enabled, provides an array of DirectoryEntry objects, similar to Stats
objects, which have the filename and the type information.

Refs: https://github.com/nodejs/node/issues/15699

PR-URL: https://github.com/nodejs/node/pull/22020


Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Roman Reiss <me@silverwind.io>
Reviewed-By: John-David Dalton <john.david.dalton@gmail.com>