feat(usage): add i18n strings for the Usage page

Menu label (Usage) and the resource-tab strings (filters, export
chart/table, table headers) across all five locales.

src/locales/en-US/menu.ts

@@ -34,6 +34,9 @@ export default {
   'menu.profile': 'Preferences',
   'menu.login': 'Login',
   'menu.usage': 'Usage',
+  'menu.usage.usage': 'Usage',
+  'menu.billingAndUsage': 'Billing & Usage',
+  'menu.billingAndUsage.usage': 'Usage',
   'menu.404': '404',
   'menu.clusterManagement': 'Cluster Management',
   'menu.clusterManagement.clusters': 'Clusters',