For some reasons when we delete a MergeTree Part in atomic way something may go wrong - and leave the `delete_tmp_*` folder or it's part on disk. This may lead to a disk space consumption over time.

It's suggested to delete this folders at least at server start-up. Current solution with `clearOldTemporaryDirectories()` doesn't work because this method is called periodically from a thread without any locks or advisory on folders - it may cause the race conditions.
({
        std::lock_guard lock(currently_fetching_parts_mutex);
        currently_fetching_parts.erase(part_name);
    });
    LOG_DEBUG(log, "Fetching part {} from {}", part_name, source_replica_path);
    TableLockHolder table_lock_holder = lockForShare(RWLockImpl::NO_QUERY, getSettings()->lock_acquire_timeout_for_background_operations);
    
    Stopwatch stopwatch;
    MutableDataPartPtr part;
    DataPartsVector replaced_parts;
    auto write_part_log = [&] (const ExecutionStatus & execution_status)
    {
        writePartLog(
            PartLogElement::DOWNLOAD_PART, execution_status, stopwatch.elapsed(),
            part_name, part, replaced_parts, nullptr);
    };
    std::function<MutableDataPartPtr()> get_part;
    ReplicatedMergeTreeAddress address(zookeeper->get(fs::path(source_replica_path) / "host"));
    auto timeouts = ConnectionTimeouts::getHTTPTimeouts(getContext());
    auto credentials = getContext()->getInterserverCredentials();
    String interserver_scheme = getContext()->getInterserverScheme();
    get_part = [&, address, timeouts, interserver_scheme, credentials]()
    {
        if (interserver_scheme != address.scheme)
            throw Exception("Interserver schemes are different: '" + interserver_scheme
                + "' != '" + address.scheme + "', can't fetch part from " + address.host,
                ErrorCodes::INTERSERVER_SCHEME_DOESNT_MATCH);
        return fetcher.fetchPart(
            metadata_snapshot, getContext(), part_name, source_replica_path,
            address.host, address.replication_port,