Made a batch object serializable

build/includes/global/message_atoms.hpp

build/includes/summa_actor/batch_manager.hpp

build/includes/summa_actor/client.hpp

build/includes/summa_actor/summa_server.hpp

build/source/actors/main.cpp

build/source/actors/summa_actor/batch_manager.cpp

build/source/actors/summa_actor/client.cpp

build/source/actors/summa_actor/summa_client.cpp

build/source/actors/summa_actor/summa_server.cpp

build/source/testing/inspector/inspector_test

build/source/testing/inspector/main.cpp

build/source/testing/inspector/main.hpp

build/source/testing/inspector/main.o