Feature request: DNS test library

[yegoratpinterest]

I need to be able to:

1. Make dynamic resolution during the runtime
2. Test DNS resolution correctness (including EDNS)
3. (Optional) Get resolution timing and other stats even though it is not strictly required

Implemented so far:
Simple resolution for A records, ie.

import dns from "k6/dns";
...
let ip = [0,0,0,0,0,0,0,0,0,0,255,255].concat(
  dns.getAllA(endpoint[cdn]['default'])[0].split("."));

Next step is to add stats and advanced features.