chore: demo page menu management (#5619)

* 添加菜单管理演示页面

apps/backend-mock/api/system/menu/list.ts

@@ -0,0 +1,12 @@
+import { verifyAccessToken } from '~/utils/jwt-utils';
+import { MOCK_MENU_LIST } from '~/utils/mock-data';
+import { unAuthorizedResponse, useResponseSuccess } from '~/utils/response';
+
+export default eventHandler(async (event) => {
+  const userinfo = verifyAccessToken(event);
+  if (!userinfo) {
+    return unAuthorizedResponse(event);
+  }
+
+  return useResponseSuccess(MOCK_MENU_LIST);
+});