Add unittests for kafka notifications

common/cpp/include/asapo/kafka_client/kafka_client.h

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

common/cpp/src/kafka_client/kafka_client_factory.cpp

deploy/asapo_helm_chart/asapo/configs/asapo-receiver.json

receiver/CMakeLists.txt

receiver/src/connection.cpp

receiver/src/connection.h

receiver/src/main.cpp

receiver/src/receiver.cpp

receiver/src/receiver.h

receiver/src/receiver_config.cpp

receiver/src/request_handler/request_factory.cpp

receiver/src/request_handler/request_factory.h

...iver/src/request_handler/request_handler_kafka_notify.cpp

receiver/src/request_handler/request_handler_kafka_notify.h

receiver/src/request_handler/requests_dispatcher.cpp

receiver/src/request_handler/requests_dispatcher.h

receiver/unittests/mock_receiver_config.cpp

receiver/unittests/request_handler/test_request_factory.cpp

...sts/request_handler/test_request_handler_kafka_notify.cpp