feat: update manifests and namespaces to use templated namespace variables

docker-registry/manifest.yaml

@@ -2,11 +2,11 @@ name: docker-registry
 is: docker-registry
 description: Private Docker image registry for cluster
 version: "3.0.0"
-namespace: docker-registry
 category: infrastructure
 requires:
   - name: traefik
   - name: cert-manager
 defaultConfig:
+  namespace: docker-registry
   host: "registry.{{ .cloud.internalDomain }}"
   storage: "100Gi"