JS frontend stuff

Move old ember frontend to properly named folder
Add vue based new frontend

frontend-old-ember/types/global.d.ts

@@ -0,0 +1,8 @@
+import '@glint/environment-ember-loose';
+import 'ember-source/types';
+
+import type EmberIntlRegistry from 'ember-intl/template-registry';
+
+declare module '@glint/environment-ember-loose/registry' {
+  export default interface Registry extends EmberIntlRegistry {}
+}