Remove use of client from CLI setup

Prior, we were using a kubeconfig client during setup of the platform
commands. The client uses the command "vcluster platform token". This
would cause an endless loop like the following:
1. you run the "vcluster platform ..." command
2. vcluster makes request to /deployments endpoint, before running
the intended command.
3. the k8s client uses vcluster to authenticate the request
4. return to step 2
The request was being made to detect the platform namespace and set
it as the default namespace for the backup management command. Now,
there is not a default that is set ahead of running the command but
if a value was not passed, the CLI will then search for the platform
namespace.

(cherry picked from commit a5622f9)

cmd/vclusterctl/cmd/platform/backup/management.go

@@ -68,10 +68,8 @@ vcluster platform backup management
 		},
 	}
 
-	platformNamespace, _ := clihelper.VClusterPlatformInstallationNamespace(context.Background())
-
 	c.Flags().StringSliceVar(&cmd.Skip, "skip", []string{}, "What resources the backup should skip. Valid options are: users, teams, accesskeys, sharedsecrets, clusters and clusteraccounttemplates")
-	c.Flags().StringVar(&cmd.Namespace, "namespace", platformNamespace, product.Replace("The namespace vCluster platform was installed into"))
+	c.Flags().StringVar(&cmd.Namespace, "namespace", "", product.Replace("The namespace vCluster platform was installed into"))
 	c.Flags().StringVar(&cmd.Filename, "filename", "backup.yaml", "The filename to write the backup to")
 	return c
 }
@@ -92,12 +90,18 @@ func (cmd *ManagementCmd) run(cobraCmd *cobra.Command) error {
 		return fmt.Errorf("there is an error loading your current kube config (%w), please make sure you have access to a kubernetes cluster and the command `kubectl get namespaces` is working", err)
 	}
 
-	isInstalled, err := clihelper.IsLoftAlreadyInstalled(cobraCmd.Context(), kubeClient, cmd.Namespace)
+	ctx := cobraCmd.Context()
+	ns, err := cmd.getNS(ctx)
+	if err != nil {
+		return err
+	}
+
+	isInstalled, err := clihelper.IsLoftAlreadyInstalled(cobraCmd.Context(), kubeClient, ns)
 	if err != nil {
 		return err
 	} else if !isInstalled {
 		answer, err := cmd.Log.Question(&survey.QuestionOptions{
-			Question:     fmt.Sprintf(product.Replace("Seems like vCluster platform was not installed into namespace %q, do you want to continue?"), cmd.Namespace),
+			Question:     fmt.Sprintf(product.Replace("Seems like vCluster platform was not installed into namespace %q, do you want to continue?"), ns),
 			DefaultValue: "Yes",
 			Options:      []string{"Yes", "No"},
 		})
@@ -106,7 +110,6 @@ func (cmd *ManagementCmd) run(cobraCmd *cobra.Command) error {
 		}
 	}
 
-	ctx := cobraCmd.Context()
 	client, err := clientpkg.New(kubeConfig, clientpkg.Options{Scheme: scheme})
 	if err != nil {
 		return err
@@ -133,3 +136,14 @@ func (cmd *ManagementCmd) run(cobraCmd *cobra.Command) error {
 	cmd.Log.Donef("Wrote backup to %s", cmd.Filename)
 	return nil
 }
+
+func (cmd *ManagementCmd) getNS(ctx context.Context) (string, error) {
+	if cmd.Namespace != "" {
+		return cmd.Namespace, nil
+	}
+	platformNamespace, err := clihelper.VClusterPlatformInstallationNamespace(ctx)
+	if err != nil {
+		return "", err
+	}
+	return platformNamespace, nil
+}