Summary:
See previous diff, let's store the collapsed state of sidebar sections in local storage.
Introduced a reusable hook to take care of that.
Changelog: Device plugins are now expanded by default, and the expand / collapse state will now be remembered across restarts
Reviewed By: passy
Differential Revision: D21903394
fbshipit-source-id: a3c0231acc0aa0877522ec328eedd09cb11aedb1
