Updates metadata and metainfo to return object metadata with
FinishCopyObject request.
https://github.com/storj/storj/issues/4474
Change-Id: I32cba5c20a943272e9b5964df1b3d6463ad212dc
Part of server-side copy implementation.
Creates the methods BeginCopyObject and FinishCopyObject in satellite/metabase/copy_object.go.
This commit makes it possible to copy objects and their segments in metabase.
https://github.com/storj/team-metainfo/issues/79
Change-Id: Icc64afce16e5e0e15b83c43cff36797bb9bd39bc