Better external IP anonymization interface

[sfraint]

Today, to use IP-address-anonymization from Netconan externally, you can do something like:

from netconan.ip_anonymization import IpAnonymizer, anonymize_ip_addr
import uuid

salt = str(uuid.uuid4())
anonymizer = IpAnonymizer(salt=salt)
anon_str = anonymize_ip_addr(anonymizer, '1.2.3.4')

But it would be nice to have a better string-based IP-address anonymization interface in the anonymizer objects themselves.

There is an existing method IpAnonymizer.anonymize(addr), but this operates on an unintuitive type (int) and relies on the caller to do all the work (i.e. convert IP address to int, check if the address needs to be anonymized).

[Kircheneer]

Possibly #186 addresses some of this?