http, tls: better support for IPv6 addresses

- Properly handle IPv6 in Host header when setting servername.
- When comparing IP addresses against addresses in the subjectAltName
  field of a certificate, format the address correctly before
  doing the string comparison.

PR-URL: https://github.com/nodejs/node/pull/14772
Fixes: https://github.com/nodejs/node/issues/14736


Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Anatoli Papirovski <apapirovski@mac.com>
Reviewed-By: James M Snell <jasnell@gmail.com>