rdf grpc: Implement consumer/producer commands #67
Description
Implement simple commands that can act as test mocks or simple emitters/collectors. Make it listen to/connect to a specific port specified by the user, and then run in the terminal until stopped.
Producer: should be able to emit any RDF data, as parsed from the input (can be Jelly). It should be able to perform stream option negotiation.
Consumer: should be able to emit the collected data as either Jelly or RDF-standard formats.