cmake HAS_PROTOBUF examples

prophesee-ai/openeb sdk/modules/stream/cpp/src/protobuf/CMakeLists.txt :61 

target_compile_definitions(metavision_device_serialization_obj PRIVATE HAS_PROTOBUF)

prophesee-ai/openeb sdk/modules/stream/cpp/tests/CMakeLists.txt :70 

target_compile_definitions(gtest_metavision_sdk_stream PRIVATE HAS_PROTOBUF)