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`
#include <Access/ContextAccess.h>
#include <Access/AllowedClientHosts.h>
#include <Databases/IDatabase.h>
#include <Storages/StorageDistributed.h>
#include <Storages/StorageReplicatedMergeTree.h>
#include <Storages/StorageFactory.h>
#include <Parsers/ASTSystemQuery.h>
#include <Parsers/ASTDropQuery.h>
#include <Parsers/ASTCreateQuery.h>
#include <csignal>
#include <algorithm>
#if !defined(ARCADIA_BUILD)
#    include "config_core.h"
#endif
namespace DB
{
namespace ErrorCodes
{
    extern const int LOGICAL_ERROR;
    extern const int BAD_ARGUMENTS;
    extern const int CANNOT_KILL;
    extern const int NOT_IMPLEMENTED;
    extern const int TIMEOUT_EXCEEDED;
    extern const int TABLE_WAS_NOT_DROPPED;
}
namespace ActionLocks
{
    extern StorageActionBlockType PartsMerge;
    extern StorageActionBlockType PartsFetch;
    extern StorageActionBlockType PartsSend;