Provide feedback from fs mode actions

[maddenp-noaa]

Description

Provide success feedback from fs mode copy, link, and makedirs actions, i.e. report which files were created/linked and directories created. Activate via a --results CLI switch or results=True API argument. For the CLI, the results report should appear on stdout; for the API, it should be the new return value from the copy(), link(), and makedirs() functions. Consider whether CLI list-of-files / API list of Paths or CLI JSON / API dict is better: The former is simpler, but the latter is extensible.

AC

• Feature implemented for CLI.
• Feature implemented for API.
• Unit test(s) added/updated.
• Documentation example(s) provided.
• Jupyter fs notebook updated with example.