Integrate tracing with a console subscriber

[ntietz]

We should have tracing to get spans and logs about the program as it executes. At first, this can use a local console subscriber to use it essentially like logging.

Out of scope: integrating with open-telemetry, but that should be an easy fast follow. Out of scope mostly because getting a local otel consumer / UI has more unknowns than I want to wrap into this one issue.

[ntietz]

Finished in #15