write file to disk

common/cpp/include/system_wrappers/io.h

common/cpp/include/system_wrappers/system_io.h

common/cpp/include/unittests/MockIO.h

common/cpp/src/system_io/system_io.cpp

receiver/src/receiver_error.h

receiver/src/request.cpp

receiver/src/request.h

receiver/src/request_handler_file_write.cpp

receiver/src/request_handler_file_write.h

receiver/unittests/test_request_handler_file_write.cpp

tests/producer_receiver/transfer_single_file/check_linux.sh

.../producer_receiver/transfer_single_file/check_windows.bat