util module is not ideal for tool packaging

[pemensik]

Could you rename util ti dnsdiag module instead? I would like to package this project into Fedora, but util module does not seem ideal from distribution perspective.

It would place util into path:

/usr/lib/python3.13/site-packages/util/dns.py
/usr/lib/python3.13/site-packages/util/shared.py
/usr/lib/python3.13/site-packages/util/whois.py

But the name is generic and nonspecific, while the content is specific to this package. I think it should import its constants either from dnsdiag.util or just dnsdiag module.