Minor linting and clarification

[eirrgang]

Description

These changes don't necessarily need to be merged directly or at all. But the minor restructuring and comments should help to clarify some of the potential "tasking" that could be expressed through some code restructuring.

Recall:

• any code details that depend on assumptions about the execution environment (or its consistency or permanence) need to be replaced with abstractions.
• possible parallelism and necessary concurrency/synchronization need to be expressed explicitly
• any time that the resource requirements change (such as going from a parallel accelerated simulator task to a single-process analysis task) is a good place to distinguish between "tasks", implemented by distinct functions and composed into a workflow by sending the results of a task object into the call for a dependent task.

Follow up

The changes here should not disrupt the current package.

I will capture more speculative changes in a separate branch so that we can see what more compartmentalization would look like.

[eirrgang]

This is far from normative, but it would be very helpful to distinguish between

• things that need to be done once for each ensemble member (and which only affect dependent tasks for that member)
• things that have different resource requirements than the simulator (such as only a single process) but which have dependencies or dependents on multiple ensemble members.