Add a command that will freeze clickhouse-server process with STOP signal and wakeup it after specified amount of time.
This is needed for testing (fault injection).

Wakeup can be done with `ShellCommand` running `sleep N && kill -CONT pid`
break;
#else
            throw Exception("SYSTEM RELOAD SYMBOLS is not supported on current platform", ErrorCodes::NOT_IMPLEMENTED);
#endif
        case Type::STOP_MERGES:
            startStopAction(ActionLocks::PartsMerge, false);
            break;
        case Type::START_MERGES:
            startStopAction(ActionLocks::PartsMerge, true);
            break;
        case Type::STOP_TTL_MERGES:
            startStopAction(ActionLocks::PartsTTLMerge, false);
            break;
        case Type::START_TTL_MERGES:
            startStopAction(ActionLocks::PartsTTLMerge, true);
            break;
        case Type::STOP_MOVES:
            startStopAction(ActionLocks::PartsMove, false);
            break;
        case Type::START_MOVES:
            startStopAction(ActionLocks::PartsMove, true);
            break;
        case Type::STOP_FETCHES:
            startStopAction(ActionLocks::PartsFetch, false);
            break;
        case Type::START_FETCHES:
            startStopAction(ActionLocks::PartsFetch, true);
            break;
        case Type::STOP_REPLICATED_SENDS:
            startStopAction(ActionLocks::PartsSend, false);