Read Authority field in Cloudflare/Google DNS response

[stevefrench39]

For some DNS queries, such as type=NS when name=subdomain.example.com, the response from Cloudflare/Google contains an Authority field instead of Answer.

This change reads the Authority field if present in order to fix a bug with getAllDNSRecords("subdomain.example.com", { resolver: "cloudflare-dns" }). Currently, instead of returning the records associated with the subdomain, it incorrectly returns an empty array because it does not read the Authority field in the NS records response. As a result, nsRecords.length = 0 which fails the nsRecords.length check here, and no requests for additional records are made.

curl --location 'https://dns.google/resolve?name=subdomain.example.com&type=NS&cd=1' \
--header 'accept: application/dns-json'

{
    "Status": 3,
    "TC": false,
    "RD": true,
    "RA": true,
    "AD": false,
    "CD": true,
    "Question": [
        {
            "name": "subdomain.example.com.",
            "type": 2
        }
    ],
    "Authority": [
        {
            "name": "example.com.",
            "type": 6,
            "TTL": 1800,
            "data": "ns.icann.org. noc.dns.icann.org. 2024041842 7200 3600 1209600 3600"
        }
    ],
    "Comment": "Response from 199.43.135.53."
}