test: refactor test-dns

* track callback invocations with common.mustCall() and
  common.mustNotCall()
* remove test in test/internet/test-dns.js that is duplicated in
  test/parallel/test-dns.js
* move tests that might perform a DNS query from test
  test/parallel/test-dns.js to test/internet/test-dns.js

PR-URL: https://github.com/nodejs/node/pull/13163


Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>