support ip in san

[gattjoe]

Addresses 544

Adds the IPv4Address Type and controls for it when generating output.

[nabla-c0d3]

Hello and thanks for looking into this.

I think we'll need to treat IP addresses separately from DNS names, similarly to the suggested output in #544 :

   DNS Subject Alternative Names:     ['server', 'server.domain']
   IP Subject Alternative Names:      ['192.168.1.10']     <- This is what I would like to see

Otherwise there's a risk of "confusion" in the console output and when performing the actual hostname validation.

The case where we're validating using an IP should be more explicit; something like (in _certificate_matches_hostname()):

    subj_alt_names = tuple([("DNS", name) for name in extract_dns_subject_alternative_names(certificate)])
    subj_alt_names.extend(tuple([("IP Address", ip_addr) for ip_addrin extract_ip_address_subject_alternative_names(certificate)]))
    
    certificate_names = {
        "subject": (tuple([("commonName", name) for name in get_common_names(cert_subject)]),),
        "subjectAltName": subj_alt_names 
    }
```

Having a small test for this would be useful too. Thanks!

[nabla-c0d3]

This was implemented in a slightly different way - see #544