archive: preserve hardlinks in Tar and Untar

Signed-off-by: Vincent Batts <vbatts@redhat.com>
archive: integration test for preserving hardlinks

Signed-off-by: Vincent Batts <vbatts@redhat.com>
archive: tests and benchmarks for hardlinks

Signed-off-by: Vincent Batts <vbatts@redhat.com>