os: add CIDR support

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

Fixes: https://github.com/nodejs/node/issues/14006

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• tests are included
• documentation is changed or added
• commit message follows commit guidelines

Affected core subsystem(s)

os