get filesize during request process, refgactor receiver errors

common/cpp/include/io/io.h

common/cpp/include/unittests/MockIO.h

common/cpp/src/system_io/system_io.h

producer/api/cpp/src/producer_request.cpp

producer/api/cpp/src/producer_request.h

producer/api/cpp/src/request_handler_tcp.cpp

producer/api/cpp/unittests/test_request_handler_tcp.cpp

receiver/src/receiver_error.h

receiver/src/request_handler_authorize.cpp

receiver/src/request_handler_db.cpp

receiver/unittests/test_request_handler_authorizer.cpp

receiver/unittests/test_request_handler_db.cpp

.../automatic/full_chain/simple_chain_filegen/check_linux.sh

...tic/producer_receiver/transfer_single_file/check_linux.sh

.../producer_receiver/transfer_single_file/check_windows.bat