**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'
```
*/
    UInt64 total_rows_on_filesystem = 0;
    for (const auto & part : parts)
        total_rows_on_filesystem += part->rows_count;
    const auto storage_settings_ptr = getSettings();
    bool insane = unexpected_parts_rows > total_rows_on_filesystem * storage_settings_ptr->replicated_max_ratio_of_wrong_parts;
    constexpr const char * sanity_report_fmt = "The local set of parts of table {} doesn't look like the set of parts in ZooKeeper: "
                                               "{} rows of {} total rows in filesystem are suspicious. "
                                               "There are {} unexpected parts with {} rows ({} of them is not just-written with {} rows), "
                                               "{} missing parts (with {} blocks).";
    if (insane && !skip_sanity_checks)
    {
        throw Exception(ErrorCodes::TOO_MANY_UNEXPECTED_DATA_PARTS, sanity_report_fmt, getStorageID().getNameForLogs(),
                        formatReadableQuantity(unexpected_parts_rows), formatReadableQuantity(total_rows_on_filesystem),
                        unexpected_parts.size(), unexpected_parts_rows, unexpected_parts_nonnew, unexpected_parts_nonnew_rows,
                        parts_to_fetch.size(), parts_to_fetch_blocks);
    }
    if (unexpected_parts_nonnew_rows > 0)
    {
        LOG_WARNING(log, sanity_report_fmt, getStorageID().getNameForLogs(),
                    formatReadableQuantity(unexpected_parts_rows), formatReadableQuantity(total_rows_on_filesystem),
                    unexpected_parts.size(), unexpected_parts_rows, unexpected_parts_nonnew, unexpected_parts_nonnew_rows,
                    parts_to_fetch.size(), parts_to_fetch_blocks);
    }
    
    std::vector<std::future<Coordination::ExistsResponse>> exists_futures;
    exists_futures.reserve(parts_to_fetch.size());
    for (const String & part_name : parts_to_fetch)
    {
        String part_path = fs::path(replica_path) / "parts" / part_name;