Chart: Improve #10539. (#10565)

* Helpers: Align `ingress-nginx.namespace` to `ingress-nginx.name`.

* Templates: Remove quotes.

In alignment to others. Also does not make sense as `namespace` must conform to DNS.

* Admission Webhooks/Validating Webhook: Make use of `ingress-nginx.namespace`.

* KEDA: Remove comment.

* Templates: Add forgotten namespace definitions.

charts/ingress-nginx/templates/default-backend-rolebinding.yaml

@@ -17,5 +17,5 @@ roleRef:
 subjects:
   - kind: ServiceAccount
     name: {{ template "ingress-nginx.defaultBackend.serviceAccountName" . }}
-    namespace: {{ (include "ingress-nginx.namespace" .) | quote }}
+    namespace: {{ include "ingress-nginx.namespace" . }}
 {{- end }}