Improve kubernetes external name service support

Co-authored-by: jbdoumenjou <jb.doumenjou@gmail.com>

integration/fixtures/k8s/02-services.yml

@@ -126,3 +126,13 @@ spec:
   selector:
     app: containous
     task: whoamiudp
+
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: externalname-svc
+  namespace: default
+spec:
+  externalName: domain.com
+  type: ExternalName

integration/fixtures/k8s/05-ingressroutetcp.yml

@@ -13,6 +13,8 @@ spec:
     - name: whoamitcp
       namespace: default
       port: 8080
+    - name: externalname-svc
+      port: 9090
   tls:
     options:
       name: mytlsoption