test: added input validation test for fchmod

Added a test to ensure input validation for FD and mode for fs.fchmod.
Removed check for values lower than 0 for `mode` as it's already checked
by `validateUint32`.

PR-URL: https://github.com/nodejs/node/pull/18217


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Anna Henningsen <anna@addaleax.net>