DNSLink Manifest JSON

[Winterhuman]

To prevent random people from creating DNSLinks from their domains to a KID of an Origin they don't own, we can introduce a new JSON config for the Manifest which states the domain the DNSLink should have, if the domain doesn't match the connection is rejected. Here's how it would look:

{
  "cache": {
    "path": null,
    "CID": null
  },
  "on_fail": null,
  "stream": {
    "path": null,
    "keyID": null
  },
  "host": "hostname",
  "dnslink": "website.tld",  [New]
  "multiaddress": ...

If someone created a DNSLink from fakewebsite.tld to KID.ipns.domain.tld, the Gateway at domain.tld would check fakewebsite.tld against website.tld within the Manifest, since they don't match the connection is rejected.