Summary: Expose a Panel api from Sandy, which is quite similar to the old one, except that it uses Antd, and it will remember the users closed / open preference through sessions, a much requested feature.
Reviewed By: nikoant
Differential Revision: D27966607
fbshipit-source-id: 9b18df377215c1e6c5844d0bf972058c8c574cbb
c005753018