chore: support load/save from GCS

[romange]

Not everything is supported but manual load save is supported.

1. Run dragonfly with --dir gs://bucket/path
2. In redis-cli: a. SET foo bar b. SAVE DF gsdump c. DFLY LOAD gs://bucket/path/gsdump-summary.dfs

[sanathkandikanti]

@romange i'm seeing build failures and i think it's related to this change, can you help

FAILED: src/server/CMakeFiles/dragonfly_lib.dir/detail/snapshot_storage.cc.o
/usr/bin/g++ -DBOOST_ALL_NO_LIB -DBOOST_ASIO_SEPARATE_COMPILATION -DBOOST_BEAST_SEPARATE_COMPILATION -DBOOST_CONTEXT_DYN_LINK -DBOOST_SYSTEM_DYN_LINK -DDFLY_ENABLE_MEMORY_TRACKING -DDFLY_USE_SSL -DGLOG_CUSTOM_PREFIX_SUPPORT -DUSE_ZMALLOC_MI -DWITH_AWS -I/home/sanathkandikanti/workplace/dragonfly -I/home/sanathkandikanti/workplace/dragonfly/genfiles -I/home/sanathkandikanti/workplace/dragonfly/src -I/home/sanathkandikanti/workplace/dragonfly/helio -I/home/sanathkandikanti/workplace/dragonfly/genfiles/src -I/home/sanathkandikanti/workplace/dragonfly/build-dbg/_deps/glog-build -I/home/sanathkandikanti/workplace/dragonfly/build-dbg/_deps/glog-src/src -I/home/sanathkandikanti/workplace/dragonfly/build-dbg/_deps/abseil_cpp-src -isystem /home/sanathkandikanti/workplace/dragonfly/build-dbg/third_party/libs/xxhash/include -isystem /home/sanathkandikanti/workplace/dragonfly/build-dbg/third_party/libs/mimalloc/include -isystem /home/sanathkandikanti/workplace/dragonfly/build-dbg/third_party/libs/lua/include -isystem /home/sanathkandikanti/workplace/dragonfly/build-dbg/third_party/libs/uring/include -isystem /home/sanathkandikanti/workplace/dragonfly/build-dbg/third_party/libs/cares/include -isystem /home/sanathkandikanti/workplace/dragonfly/build-dbg/third_party/libs/reflex/include -isystem /home/sanathkandikanti/workplace/dragonfly/build-dbg/third_party/libs/uni-algo/include -isystem /home/sanathkandikanti/workplace/dragonfly/build-dbg/third_party/libs/hnswlib/include -isystem /home/sanathkandikanti/workplace/dragonfly/build-dbg/third_party/libs/jsoncons/include -isystem /home/sanathkandikanti/workplace/dragonfly/build-dbg/third_party/libs/flatbuffers/include -isystem /home/sanathkandikanti/workplace/dragonfly/build-dbg/third_party/libs/dconv/include -isystem /home/sanathkandikanti/workplace/dragonfly/build-dbg/third_party/libs/fast_float/include -isystem /home/sanathkandikanti/workplace/dragonfly/build-dbg/third_party/libs/gperf/include -isystem /home/sanathkandikanti/workplace/dragonfly/build-dbg/third_party/libs/aws/include -isystem /home/sanathkandikanti/workplace/dragonfly/build-dbg/third_party/libs/rapidjson/include -isystem /home/sanathkandikanti/workplace/dragonfly/build-dbg/third_party/libs/lz4/include -isystem /home/sanathkandikanti/workplace/dragonfly/build-dbg/third_party/libs/croncpp/include -Wall -Wextra -g -fPIC -fno-builtin-malloc -fno-builtin-calloc -fno-builtin-realloc -fno-builtin-free -fno-omit-frame-pointer -Wno-unused-parameter -march=sandybridge -mtune=skylake -Wno-use-after-free  -std=c++20 -DHAS_RAWMEMCHR -fdiagnostics-color=always  -g -std=gnu++17 -MD -MT src/server/CMakeFiles/dragonfly_lib.dir/detail/snapshot_storage.cc.o -MF src/server/CMakeFiles/dragonfly_lib.dir/detail/snapshot_storage.cc.o.d -o src/server/CMakeFiles/dragonfly_lib.dir/detail/snapshot_storage.cc.o -c /home/sanathkandikanti/workplace/dragonfly/src/server/detail/snapshot_storage.cc
/home/sanathkandikanti/workplace/dragonfly/src/server/detail/snapshot_storage.cc: In member function ‘virtual io::Result<std::pair<io::Sink*, unsigned char>, dfly::GenericError> dfly::detail::GcsSnapshotStorage::OpenWriteFile(const std::string&)’:
/home/sanathkandikanti/workplace/dragonfly/src/server/detail/snapshot_storage.cc:224:56: error: ‘CreateApiConnectionPool’ is not a member of ‘util::cloud::GCS’
  224 |   unique_ptr<http::ClientPool> conn_pool = cloud::GCS::CreateApiConnectionPool(ctx_, proactor);
      |                                                        ^~~~~~~~~~~~~~~~~~~~~~~
/home/sanathkandikanti/workplace/dragonfly/src/server/detail/snapshot_storage.cc:225:10: error: ‘GcsWriteFileOptions’ is not a member of ‘util::cloud’
  225 |   cloud::GcsWriteFileOptions opts;
      |          ^~~~~~~~~~~~~~~~~~~
/home/sanathkandikanti/workplace/dragonfly/src/server/detail/snapshot_storage.cc:226:3: error: ‘opts’ was not declared in this scope
  226 |   opts.creds_provider = &creds_provider_;
      |   ^~~~
/home/sanathkandikanti/workplace/dragonfly/src/server/detail/snapshot_storage.cc: In member function ‘virtual io::ReadonlyFileOrError dfly::detail::GcsSnapshotStorage::OpenReadFile(const std::string&)’:
/home/sanathkandikanti/workplace/dragonfly/src/server/detail/snapshot_storage.cc:245:56: error: ‘CreateApiConnectionPool’ is not a member of ‘util::cloud::GCS’
  245 |   unique_ptr<http::ClientPool> conn_pool = cloud::GCS::CreateApiConnectionPool(ctx_, proactor);
      |                                                        ^~~~~~~~~~~~~~~~~~~~~~~
/home/sanathkandikanti/workplace/dragonfly/src/server/detail/snapshot_storage.cc:246:10: error: ‘GcsReadFileOptions’ is not a member of ‘util::cloud’
  246 |   cloud::GcsReadFileOptions opts;
      |          ^~~~~~~~~~~~~~~~~~
/home/sanathkandikanti/workplace/dragonfly/src/server/detail/snapshot_storage.cc:247:3: error: ‘opts’ was not declared in this scope
  247 |   opts.creds_provider = &creds_provider_;
      |   ^~~~
/home/sanathkandikanti/workplace/dragonfly/src/server/detail/snapshot_storage.cc:251:17: error: ‘OpenReadGcsFile’ is not a member of ‘util::cloud’; did you mean ‘OpenWriteGcsFile’?
  251 |   return cloud::OpenReadGcsFile(bucket, key, opts);
      |                 ^~~~~~~~~~~~~~~
      |                 OpenWriteGcsFile
[550/575] Building CXX object src/server/CMakeFiles/dragonfly_lib.dir/set_family.cc.o
ninja: build stopped: subcommand failed.

[romange]

git submodule update

[sanathkandikanti]

Thank you