os: add CIDR support

This patch adds support for CIDR notation to the output of the
`networkInterfaces()` method

PR-URL: https://github.com/nodejs/node/pull/14307
Fixes: https://github.com/nodejs/node/issues/14006


Reviewed-By: Roman Reiss <me@silverwind.io>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Timothy Gu <timothygu99@gmail.com>