s4/drs: re-implement 'renaming' object replication

s4/drs: re-implement 'renaming' object replication

We should rename objects only after we make sure, that
changes on the partner DC are newer than what we have.
This fixes a bug, when we have following situation with 2 DCs:
- we have an object O on the two DCs
- we rename (delete) object O on DC1
- DC1 replicates from DC2
In the above scenario, object O will be renamed back
to its original name (i.e. it will be restored).

Now, we check that DC2 state is older than what we have,
so nothing happens with object's DN.