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?
#       include "Common/BitonicSort.h" 
#   endif
#endif
#if defined(OS_LINUX)
#    include <sys/mman.h>
#    include <sys/ptrace.h>
#    include <Common/hasLinuxCapability.h>
#    include <unistd.h>
#    include <sys/syscall.h>
#endif
#if USE_SSL
#    if USE_INTERNAL_SSL_LIBRARY  && !defined(ARCADIA_BUILD)
#        include <Compression/CompressionCodecEncrypted.h>
#    endif
#    include <Poco/Net/Context.h>
#    include <Poco/Net/SecureServerSocket.h>
#endif
#if USE_GRPC
#   include <Server/GRPCServer.h>
#endif
#if USE_NURAFT
#   include <Server/KeeperTCPHandlerFactory.h>
#endif
#if USE_BASE64
#   include <turbob64.h>
#endif
#if USE_JEMALLOC
#    include <jemalloc/jemalloc.h>
#endif
namespace CurrentMetrics