Add getUser back as deprecated method

Summary: On downloading  the new flipper update some of the older plugins which are on a different release cycle may try to call getUser which was removed in this stack in favour of getCached user and fetchUser, adding this back temporarily so those calls dont fail. This can be removed down the road once those plugins have soaked into the user base

Reviewed By: ivanmisuno, aigoncharov

Differential Revision: D44541277

fbshipit-source-id: 95e67d5ba11bbc26590d2789127cbf6a68c54f16

desktop/flipper-ui-core/src/deprecated-exports.tsx

@@ -20,6 +20,7 @@ export {
   internGraphPOSTAPIRequest,
   graphQLQuery,
   isLoggedIn,
+  getUser,
   fetchUser,
   getCachedUser,
 } from './fb-stubs/user';

desktop/flipper-ui-core/src/fb-stubs/user.tsx

@@ -18,6 +18,10 @@ export function getCachedUser(): User | null {
   return null;
 }
 
+export function getUser(): Promise<User | null> {
+  return fetchUser();
+}
+
 export async function internGraphPOSTAPIRequest(
   _endpoint: string,
   _formFields: {