prints errors caught in the pysmurf-controller subprocesses

[jlashner]

Logs errors in pysmurf-controller subprocess.

Description

We are seeing that since the subprocessing change, failures in pysmurf-controller operations are not logging exceptions that are thrown (though the tracebacks are being stored in session.data). This PR adds a log of the traceback when an exception is caught in the subprocess.

Motivation and Context

See here for an example: https://github.com/simonsobs/daq-discussions/discussions/95

How Has This Been Tested?

Not tested yet

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.