**Use case**

Currently, `system.replicas` table has `total_replicas` and `active_replicas` columns which are useful to check/alert when some replicas are down. One problem, these columns are numbers. They tell when there is a problem, but you need to further check ZooKeeper or query all the nodes to detect what exact replicas (hosts) are down/inactive/have problems.

**Describe the solution you'd like**

Add a replicas column maybe as a map which would contain the replica name, and it's status. Or, add 2 array columns with `replica_names` and `active_replica_names`

**Alternative**

Something along the line

```sql
select path, value from system.zookeeper where path IN (
    select concat(path, '/', name) from system.zookeeper where path in (select concat(zookeeper_path, '/replicas') from system.replicas)
)
and name = 'is_active'
```
zkutil::KeeperMultiException::check(rc, ops, responses);
        }
    }
    std::sort(source_queue_names.begin(), source_queue_names.end());
    Strings source_queue;
    for (const String & entry_name : source_queue_names)
    {
        String entry;
        if (!zookeeper->tryGet(fs::path(source_path) / "queue" / entry_name, entry))
            continue;
        source_queue.push_back(entry);
    }
    
    cloneMetadataIfNeeded(source_replica, source_path, zookeeper);
    
    Strings source_replica_parts = zookeeper->getChildren(fs::path(source_path) / "parts");
    ActiveDataPartSet active_parts_set(format_version, source_replica_parts);
    Strings active_parts = active_parts_set.getParts();
    
    Strings local_parts_in_zk = zookeeper->getChildren(fs::path(replica_path) / "parts");
    Strings parts_to_remove_from_zk;
    for (const auto & part : local_parts_in_zk)
    {
        if (active_parts_set.getContainingPart(part).empty())
        {
            parts_to_remove_from_zk.emplace_back(part);
            LOG_WARNING(log, "Source replica does not have part {}. Removing it from ZooKeeper.", part);
        }
    }
    {