Convenience for constructing service clients in a non Lagom server application.
It is important to invoke #stop when the application is no longer needed, as this will trigger the shutdown
of all thread and connection pools.
Stop the application.
The name of the topic publisher.
Since topic publishers don't actually provide any components, they just consume a LagomServer and publish the
topics they find there, this can be used to signal that a topic publisher has been provided to publish
topics, so that the LagomServerComponents can detect a misconfiguration where one hasn't been provided.
The name of the topic publisher that has published topics, if one has been provided.