feat: Convert all app files to JS

packages/backend/src/apps/notion/common/get-current-user.js

@@ -0,0 +1,9 @@
+const getCurrentUser = async ($) => {
+  const userId = $.auth.data.owner.user.id;
+  const response = await $.http.get(`/v1/users/${userId}`);
+
+  const currentUser = response.data;
+  return currentUser;
+};
+
+export default getCurrentUser;