Pass plugins via ipc instead of env to fix loading of plugins on Windows

Summary: Fixed the issue with empty plugin list on Windows because of env var length limit

Reviewed By: passy

Differential Revision: D19411466

fbshipit-source-id: 7fa390f7dd342e23e965b2135fbeb8e88e5857ef

__mocks__/electron.tsx

@@ -20,4 +20,5 @@ module.exports = {
     },
     getCurrentWindow: () => ({isFocused: () => true}),
   },
+  ipcRenderer: {},
 };