Rename {un,}compressedDigest to {un,}compressedDigester
Rename {un,}compressedDigest to {un,}compressedDigester

We will need ...Digest variables to hold the actual values.

Should not change behavior.

Signed-off-by: Miloslav Trmač <9c008e38982a5397deb855345fb164f0558459ae@redhat.com>

containers/storage,containers/storage,containers/storage