Get rid of perf_hooks package in Flipper UI

Summary:
perf_hooks is no longer needed as these APIs are widely available in both browser and electron.

Still needed in unit tests, as they run from Node

Reviewed By: lblasa, aigoncharov

Differential Revision: D32648253

fbshipit-source-id: 5718ea99b57f96f6858311fd0815ad18c476c99e

desktop/babel-transformer/src/electron-requires.ts

@@ -34,7 +34,6 @@ const BUILTINS = [
   'assert',
   'util',
   'path',
-  'perf_hooks',
   'punycode',
   'querystring',
   'cluster',