LP#1770478: Offline org unit tree can break

LP#1770478: Offline org unit tree can break

A thinko in the org tree reconstruction for offline mode caused the tree to be
broken in some situations, when the orgs were not ordered strictly by ID in
the list stored in the browser's IndexedDB storage.  This commit removes that
requirement, and allows trees of any ID and storage ordering to be
reconstituted.

Signed-off-by: Mike Rylander <mrylander@gmail.com>
Signed-off-by: Jeff Davis <jdavis@sitka.bclibraries.ca>
Signed-off-by: Jason Stephenson <jason@sigio.com>