[FEAT] Bubble errors up from workflows (or document how to debug errors)

[lilyminium]

Is your feature request related to a problem? Please describe.

When something goes wrong, an exception is raised in a workflow protocol and a WorkflowException is given in two ways:

• in the protocol output JSON saved in the working directory, which typically has an informative message
• returned to the EvaluatorClient as a "WorkflowException(None)"

This latter message is fairly unhelpful and confusing, especially to new users. This is especially the case since the default EvaluatorServer sets delete_working_files=True, which means that when the server stops due to an error happening, all the working data with the complete error message is also deleted.

Describe the solution you'd like

It would be great if the workflow exception message in the protocol could somehow bubble back up to the client.

Describe alternatives you've considered

Additional context

How I debug: I navigate to the working-directory/SimulationLayer/<run-hash>, less all the */*.json files, and go through them one-by-one until I hit the error.

[mattwthompson]

Sounds like a good idea to me