Add argument for v4_only=True

[bra1ncramp]

💡 Summary

Add an argument switch to set v4_only=True to the command to return only IPv4 addresses.

Motivation and context

Allowing this to be declared as a command argument instead of editing the python file directly would make this more usable.

Implementation notes

add something like --ipv4-only to set v4_only=True with default set to v4_only=False