`DataTypeFactory::get` locks a mutex inside shared a context, there was a case when many threads were locked inside it

https://pastila.nl/?0043b3e6/c557368f4cf0eb87a3c6f2cc162bc693

It is not clear which thread locked the mutex for a long time. However, it may be possible to lock less inside `DataTypeFactory::get`.
background_merges_mutations_concurrency_ratio = config.getUInt64("background_merges_mutations_concurrency_ratio");
    else if (config.has("profiles.default.background_pool_size"))
        background_merges_mutations_concurrency_ratio = config.getUInt64("profiles.default.background_merges_mutations_concurrency_ratio");
    size_t background_move_pool_size = 8;
    if (config.has("background_move_pool_size"))
        background_move_pool_size = config.getUInt64("background_move_pool_size");
    else if (config.has("profiles.default.background_move_pool_size"))
        background_move_pool_size = config.getUInt64("profiles.default.background_move_pool_size");
    size_t background_fetches_pool_size = 8;
    if (config.has("background_fetches_pool_size"))
        background_fetches_pool_size = config.getUInt64("background_fetches_pool_size");
    else if (config.has("profiles.default.background_fetches_pool_size"))
        background_fetches_pool_size = config.getUInt64("profiles.default.background_fetches_pool_size");
    size_t background_common_pool_size = 8;
    if (config.has("background_common_pool_size"))
        background_common_pool_size = config.getUInt64("background_common_pool_size");
    else if (config.has("profiles.default.background_common_pool_size"))
        background_common_pool_size = config.getUInt64("profiles.default.background_common_pool_size");
    
    shared->merge_mutate_executor = std::make_shared<MergeMutateBackgroundExecutor>
    (
        "MergeMutate",
        background_pool_size,
        background_pool_size * background_merges_mutations_concurrency_ratio,
        CurrentMetrics::BackgroundMergesAndMutationsPoolTask
    );
    LOG_INFO(shared->log, "Initialized background executor for merges and mutations with num_threads={}, num_tasks={}",
        background_pool_size, background_pool_size * background_merges_mutations_concurrency_ratio);
    shared->moves_executor = std::make_shared<OrdinaryBackgroundExecutor>
    (