Core: simultaneous create/delete against same id can cause silently inconsistent replica

If simultaneous create & delete operations arrive against the same id,
it's possible that primary and replica see those operations in
different orders, which may result in replica throwing
DocumentAlreadyExistsException when the primary didn't which would
lead to replica being inconsistent (missing a document that primary
had indexed).

This push fixes the issue, by never throwing DAEE from the replica on
create.

Closes #7146 #7142