Write a file `uuid` in server's data directory that contains random UUID, generated at startup if file does not exist.

It will be used for several purposes:
- to anonymously identify server in Sentry (currently Sentry is unusable);
- (possible future usage) to identify server in ensemble.

@tavplubix comments?
ConfigProcessor config_processor(config_path);
        loaded_config = config_processor.loadConfigWithZooKeeperIncludes(
            main_config_zk_node_cache, main_config_zk_changed_event,  true);
        config_processor.savePreprocessedConfig(loaded_config, config().getString("path", DBMS_DEFAULT_PATH));
        config().removeConfiguration(old_configuration.get());
        config().add(loaded_config.configuration.duplicate(), PRIO_DEFAULT, false);
    }
    Settings::checkNoSettingNamesAtTopLevel(config(), config_path);
    const auto memory_amount = getMemoryAmount();
#if defined(OS_LINUX)
    std::string executable_path = getExecutablePath();
    if (!executable_path.empty())
    {
        
        
        
        
        
        
        
        
        String calculated_binary_hash = getHashOfLoadedBinaryHex();
        if (stored_binary_hash.empty())
        {
            LOG_WARNING(log, "Calculated checksum of the binary: {}."
                " There is no information about the reference checksum.", calculated_binary_hash);
        }
        else if (calculated_binary_hash == stored_binary_hash)
        {
            LOG_INFO(log, "Calculated checksum of the binary: {}, integrity check passed.", calculated_binary_hash);