UI: Fix missing nav links on namespace login (hashicorp#12478)

* Override loading behavior which breaks query params passed to API calls

* Only show loading state if transition is not queryparams only

* Add changelog

* Skip loader if testing

changelog/12478.txt

@@ -0,0 +1,3 @@
+```release-note:fix
+ui: fix missing navbar items on login to namespace
+```

ui/app/routes/vault/cluster.js

@@ -110,5 +110,17 @@ export default Route.extend(ModelBoundaryRoute, ClusterRoute, {
       }
       return true;
     },
+    loading(transition) {
+      if (transition.queryParamsOnly || Ember.testing) {
+        return;
+      }
+      // eslint-disable-next-line ember/no-controller-access-in-routes
+      let controller = this.controllerFor('vault.cluster');
+      controller.set('currentlyLoading', true);
+
+      transition.finally(function() {
+        controller.set('currentlyLoading', false);
+      });
+    },
   },
 });

ui/app/templates/vault/cluster.hbs

@@ -113,16 +113,20 @@
     {{/flash-message}}
   {{/each}}
 </div>
-{{#if showNav}}
-  <UiWizard>
-    <section class="section">
-      <div class="container is-widescreen">
-        <TokenExpireWarning @expirationDate={{auth.tokenExpirationDate}}>
-          {{outlet}}
-        </TokenExpireWarning>
-      </div>
-    </section>
-  </UiWizard>
+{{#if currentlyLoading}}
+  <LogoSplash />
 {{else}}
-  {{outlet}}
-{{/if}}
+  {{#if showNav}}
+    <UiWizard>
+      <section class="section">
+        <div class="container is-widescreen">
+          <TokenExpireWarning @expirationDate={{auth.tokenExpirationDate}}>
+            {{outlet}}
+          </TokenExpireWarning>
+        </div>
+      </section>
+    </UiWizard>
+  {{else}}
+    {{outlet}}
+  {{/if}}
+{{/if}}