Cleanup MongoDB cpp communication

common/cpp/include/asapo/database/database.h

common/cpp/include/asapo/unittests/MockDatabase.h

common/cpp/src/database/mongodb_client.cpp

common/cpp/src/database/mongodb_client.h

receiver/CMakeLists.txt

receiver/src/request_handler/request_factory.cpp

receiver/src/request_handler/request_factory.h

.../src/request_handler/request_handler_db_delete_stream.cpp

...er/src/request_handler/request_handler_db_delete_stream.h

receiver/src/request_handler/request_handler_db_get_meta.cpp

receiver/src/request_handler/request_handler_db_get_meta.h

...er/src/request_handler/request_handler_db_last_stream.cpp

...iver/src/request_handler/request_handler_db_last_stream.h

...src/request_handler/request_handler_db_persist_stream.cpp

...r/src/request_handler/request_handler_db_persist_stream.h

...er/src/request_handler/request_handler_db_stream_info.cpp

...iver/src/request_handler/request_handler_db_stream_info.h

receiver/unittests/monitoring/test_monitoring_client.cpp

...sts/monitoring/test_monitoring_client_to_be_send_data.cpp

receiver/unittests/request_handler/test_request_factory.cpp