[7.x] Registered domain processor (#67611)

[danhermann]

This PR adds support for a processor that looks up the registered domain, eTLD from the public suffix list, and uses those to split out the subdomain as well. It's essentially a port of the beats processor.

➜  ~ curl -H "Content-Type: application/json" -X POST -u elastic:password http://localhost:9200/_ingest/pipeline/_simulate\?verbose --data-binary @- << EOF
{
  "pipeline": {
    "processors": [
      {
        "registered_domain": {
          "field": "url",
          "target_field": "url_registered_domain"
        }
      }
    ]
  },
  "docs": [
    {
      "_source": {
        "url": "www.google.com"
      }
    }
  ]
}

Produces:

...
"_source" : {
  "url_registered_domain" : {
    "subdomain": "www",
    "registered_domain": "google.com",
    "top_level_domain": "com"
  }
  "url": "www.google.com"
}
...

Backport of #67611

[elasticmachine]

Pinging @elastic/es-core-features (Team:Core/Features)