Fixup #2970: Add Missing Label app.kubernetes.io/part-of: ingress-nginx

-    Add missing label `app.kubernetes.io/part-of: ingress-nginx` for deploy example
-    Update new labels for docs/deploy and docs/examples
-    Update new labels for test/e2e and test/manifests
-    Update new labels for images/nginx

Also close #3001

test/e2e/wait-for-nginx.sh

@@ -28,7 +28,7 @@ function on_exit {
     test $error_code == 0 && return;
 
     echo "Obtaining ingress controller pod logs..."
-    kubectl logs -l app=ingress-nginx -n $NAMESPACE
+    kubectl logs -l app.kubernetes.io/name=ingress-nginx -n $NAMESPACE
 }
 trap on_exit EXIT