Merges most of `wp.media.controller.Upload` into `wp.media.controller.Library`, so we always create an inline uploader instead of an attachments browser if the state's `library` is empty.
props rzen, fixes#22323, see #21390.
git-svn-id: https://develop.svn.wordpress.org/trunk@22363 602fd350-edb4-49c9-b593-d223f7449a82