[2SP] CMW: Review subscription mechanism/filtering wrt GnuRadioAcquisition Worker

[ivan-cukic]

It is easy to overload sink with tons of slightly different listeners.

Limit the space of different subscriptions that can be subscribed to,
for example, limit the number of pre/postsamples to powers of 2.

[frankosterfeld]

How would we do this in a generic way, without hardcoding GnuRadioAcquisitionWorker specifics in opencmw-cpp? It would need a way for the worker to describe the possibilities without spelling out all permutations 🤔