parallel connections work

broker/src/asapo_broker/database/database.go

broker/src/asapo_broker/database/database_test.go

broker/src/asapo_broker/database/mock_database.go

broker/src/asapo_broker/database/mongodb.go

broker/src/asapo_broker/database/mongodb_test.go

broker/src/asapo_broker/server/get_id.go

broker/src/asapo_broker/server/get_id_test.go

broker/src/asapo_broker/server/get_next.go

broker/src/asapo_broker/server/listroutes.go

broker/src/asapo_broker/utils/status_codes.go

common/cpp/include/common/error.h

common/cpp/include/preprocessor/definitions.h

common/cpp/src/http_client/CMakeLists.txt

...ples/producer/dummy-data-producer/dummy_data_producer.cpp

examples/worker/getnext_broker/getnext_broker.cpp

producer/api/src/receiver_discovery_service.cpp

producer/api/src/receiver_discovery_service.h

producer/api/src/request_handler_factory.h

producer/api/src/request_handler_tcp.cpp

producer/api/src/request_pool.h