feat: manage externaldns bind (#428)

- add module to manage externaldns bind for k8s
- add infra::dns::externaldns role
- add 198.18.19.20 as anycast for k8s external-dns service

Reviewed-on: #428

site/roles/manifests/infra/dns/externaldns.pp

@@ -0,0 +1,11 @@
+# BIND server role for ExternalDNS integration
+class roles::infra::dns::externaldns {
+  if $facts['firstrun'] {
+    include profiles::defaults
+    include profiles::firstrun::init
+  } else {
+    include profiles::defaults
+    include profiles::base
+    include externaldns
+  }
+}