update content loading and error handling

unwind error handling

use auth cookie as source of truth, fetch config only when authenticated

src/components/ContentLoading.jsx

@@ -0,0 +1,19 @@
+import React from 'react';
+import { t } from '@lingui/macro';
+import { withI18n } from '@lingui/react';
+import {
+  EmptyState,
+  EmptyStateBody
+} from '@patternfly/react-core';
+
+// TODO: Better loading state - skeleton lines / spinner, etc.
+const ContentLoading = ({ i18n }) => (
+  <EmptyState>
+    <EmptyStateBody>
+      {i18n._(t`Loading...`)}
+    </EmptyStateBody>
+  </EmptyState>
+);
+
+export { ContentLoading as _ContentLoading };
+export default withI18n()(ContentLoading);