feat: Convert all app files to JS

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

@@ -0,0 +1,8 @@
+const getCurrentUser = async ($) => {
+  const { data: currentUser } = await $.http.get(
+    'https://people.googleapis.com/v1/people/me?personFields=names,emailAddresses'
+  );
+  return currentUser;
+};
+
+export default getCurrentUser;