=str #16085 PublisherSink is no longer a singleton

* PublisherSink is no longer a singleton
* rename existing Source/Sink tests to the latest names
* uncomment TickSource test with Zip

Fixes #16085
is the visibility of these things correct? when does the user have to care about KeyedActorFlowSink, ActorFlowSink, SimpleActorFlowSink?
//cc @bantonsson