Manipulating workspace secrets from CLI

## What example? Describe it

First some form of script that uses the CLI to store a key passed as input in the workspace keyvault, ideally using something like `az keyvault secret set ...`. It'd also be nice to show how some job can access that key, preferably without the python rigmarole.

## Additional context

The Azure ML VSCode extension is organized around the CLI rather than the Python SDK. It'd be good to have the same functionality in each.

Thanks for your time,
Sean

No files, tests, or example locations are named. Start by reviewing the repository's existing CLI-oriented Azure Machine Learning examples, then determine how to demonstrate storing a workspace secret with `az keyvault secret set` and accessing it from a job without the Python SDK; done means both workflows are documented and runnable.

Written by the indexing model from the issue text.