Import zdfs package to support a tricky OCIv1 tgz format

[BigVan]

What this PR does / why we need it: Add zdfs package import. Packing the reference files of the overlaybd blob into the layer of the OCIv1 image; This enables the old version of containerd or other runtime (such as docker) to run overlaybd image

reference files like:

ls /var/lib/containerd/io.containerd.snapshotter.v1.overlaybd/snapshots/283/fs -a
.aaaaaaaaaaaaaaaa.lsmt  .checksum_file  .data_size  .oss_url  .type

# .oss_url is the overlaybd blob uploaded address in remote storage
# .data_size is the blobSize record in the annotation of overlaybd image manifest.
# other files can be empty

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged): Fixes #

Please check the following list:

• [ ] Does the affected code have corresponding tests, e.g. unit test, E2E test?
• [ ] Does this change require a documentation update?
• [ ] Does this introduce breaking changes that would require an announcement or bumping the major version?
• [ ] Do all new files have an appropriate license header?

[liulanzheng]

LGTM @WaberZhuang cc