message: Emit remove_object() instructions for embedded objects
  The object store notification code needs these. The sync replication log
  doesn't, but it can filter out embedded objects itself.
diff: @@ -1390,11 +1390,9 @@ size_t Cluster::erase(ObjKey key, CascadeState& state)
  ObjKey real_key = get_real_key(ndx);
  auto table = m_tree_top.get_owner();
  const_cast<Table*>(table)->free_local_id_after_hash_collision(real_key);
  - if (!table->is_embedded()) {
  if (Replication* repl = table->get_repl()) {
  repl->remove_object(table, real_key);
  }
  - }
  std::vector<ColKey> backlink_column_keys;
  