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.
UInt64 unexpected_parts_nonnew_rows = 0;
    UInt64 unexpected_parts_rows = 0;
    for (const auto & part : unexpected_parts)
    {
        if (part->info.level > 0)
        {
            ++unexpected_parts_nonnew;
            unexpected_parts_nonnew_rows += part->rows_count;
        }
        unexpected_parts_rows += part->rows_count;
    }
    const UInt64 parts_to_fetch_blocks = std::accumulate(parts_to_fetch.cbegin(), parts_to_fetch.cend(), 0,
        [&](UInt64 acc, const String& part_name)
        {
            if (const auto part_info = MergeTreePartInfo::tryParsePartName(part_name, format_version))
                return acc + part_info->getBlocksCount();
            LOG_ERROR(log, "Unexpected part name: {}", part_name);
            return acc;
        });
    /** We can automatically synchronize data,
      *  if the ratio of the total number of errors to the total number of parts (minimum - on the local filesystem or in ZK)
      *  is no more than some threshold (for example 50%).
      *
      * A large ratio of mismatches in the data on the filesystem and the expected data
      *  may indicate a configuration error (the server accidentally connected as a replica not from right shard).
      * In this case, the protection mechanism does not allow the server to start.
      */
    UInt64 total_rows_on_filesystem = 0;
    for (const auto & part : parts)
        total_rows_on_filesystem += part->rows_count;