first draft of persisted streams

broker/src/asapo_broker/database/mongodb.go

broker/src/asapo_broker/server/listroutes.go

broker/src/asapo_broker/server/post_persist_stream.go

broker/src/asapo_broker/server/server.go

common/cpp/include/asapo/common/networking.h

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

consumer/api/c/include/asapo/consumer_c.h

consumer/api/cpp/include/asapo/consumer/consumer.h

consumer/api/cpp/src/consumer_c_glue.cpp

consumer/api/cpp/src/consumer_impl.cpp

consumer/api/cpp/src/consumer_impl.h

consumer/api/python/asapo_consumer.pxd

consumer/api/python/asapo_consumer.pyx.in

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

deploy/asapo_services/scripts/receiver.json.tpl

producer/api/c/include/asapo/producer_c.h

producer/api/cpp/include/asapo/producer/producer.h