Merge data protocol into control protocol?

[BenediktBurger]

Original place: pymeasure/pyleco#89

Maybe we should scap the idea of the (PUB-SUB based) data protocol, and implement it via the control protocol.
That what make the whole setup more simple.

Reasoning

The data protocol infrastructure is not as flexible, as messages can flow only in one direction (from server to server).
Due to the different architectures of the data and control protocol networks, you might want to subscribe to a publishing actor, which you cannot reach via the data protocol.

We can, however use the control protocol to subscribe and to publish messages. (managing the subscribers manually)

This reflects the experience from #2 (comment) that it is quite simple to use the control protocol only. PUB-SUB does not save on bandwidth anyway.

[BenediktBurger]

Only downside: with the pub sub Infrastrukturen, you can subscriben to all publisher or all publishers starting with a certain namespace/Name. By subscribing to a topic "" or "namespace"

However, you could request all Components from a Coordinator and subscribe to all of them individually.

[BenediktBurger]

Another idea raised by a collaborator: Use the COORDINATOR (of the control protocol) or some other server as a proxy server relaying messages from publishers to subscribers.
Pro: No subscriber handling on publisher side.
Con: How to connect the proxy servers? And you have to send a message from the publisher to the proxy, even if there is no subscriber at all.