update c++ part

CHANGELOG.md

common/cpp/include/asapo/common/error.h

common/cpp/include/asapo/request/request.h

common/cpp/include/asapo/request/request_pool_error.h

common/cpp/src/request/request_pool.cpp

common/cpp/unittests/request/test_request_pool.cpp

consumer/api/python/asapo_consumer.pxd

producer/api/cpp/include/asapo/producer/producer_error.h

producer/api/cpp/src/producer_impl.cpp

producer/api/cpp/unittests/test_producer_impl.cpp