feat: add gcp dns-zone module

[maxsxu]

Motivation

To help customer configure new sub DNS zone.

How to use?

module "gcp-dns-zone" {
  source = "github.com/streamnative/terraform-managed-cloud//modules/gcp/dns-zone"

  source_project = "<input-project-holds-source-zone>"
  target_project = "<input-project-holds-target-zone>"

  source_zone_name     = "<input-source-zone>"
  target_zone_name     = "<input-target-zone>"
  target_zone_dns_name = "<input-target-dns>"
}

[maxsxu]

Typically, the parent zone might not live in GCP but in other providers, e.g, GoDaddy

So this module doesn't fit for these scenarios.