Plan for stanislav-shchetinin

[Gazizonoki]

• Replace TAutoPtr to std::unique_ptr #73
• Replace TSharedPtr to std::shared_ptr #72
• Replace THolder to std::unique_ptr #65
• Replace TAtomic to std::atomic #62
• Move vector_index example from ydb repo #258
• Implement integration tests environment for SDK #273
• Add BulkUpsert integration test #279
• Move grpc_client_low unit test from ydb repo #289