suites: adding dencoder test multi versions

suites: adding dencoder test multi versions

We are currently conducting regular ceph-dencoder tests for backward compatibility.
However, we are omitting tests for forward compatibility.
This suite will introduce tests against the ceph-objects-corpus to address forward
compatibility issues that may arise.
the script will install N-2 version and run against the latest version corpus objects
that we have, then install N-1 to N version and check them as well.

Signed-off-by: Nitzan Mordechai <nmordech@redhat.com>