Add new snapshotter & differ plugins that can leverage the block CIM layer writers to
store pulled/imported images in the block CIM format.
Signed-off-by: Amit Barve <ambarve@microsoft.com>
hcsshim recently [updated](microsoft/hcsshim@1d406d0) the interface of APIs that are used
for importing OCI layers. It now expects that the CimFS snapshotter mounts contain the
full cim paths for parent layers. This change updates the cimfs differ & snapshotter to
use that new interface.
Signed-off-by: Amit Barve <ambarve@microsoft.com>