dns: type check for dns.setServers argument.

Added type check for argument for dns.setServers and dnsPromises.setServers.

PR-URL: https://github.com/nodejs/node/pull/21944


Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Jon Moss <me@jonathanmoss.me>
Reviewed-By: Yuta Hiroto <hello@hiroppy.me>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Сковорода Никита Андреевич <chalkerx@gmail.com>