azure-cli-extensions Add code documentation and fix Unbound exceptions

This PR is an example of using AI to add documentation to code and Github Copilot to find bugs to fix. This PR adds code documentation to the big custom.py file. This also fixes an Unbound exception bug in the existing_rg and copy_disk_id variables. Fixed a duplicate test name error.

This checklist is used to make sure that common guidelines for a pull request are followed.

Related command

General Guidelines

[x] Have you run azdev style <YOUR_EXT> locally? (pip install azdev required)
[x] Have you run python scripts/ci/test_index.py -q locally? (pip install wheel==0.30.0 required)
[x] My extension version conforms to the Extension version schema

For new extensions:

[x] My extension description/summary conforms to the Extension Summary Guidelines.

About Extension Publish

There is a pipeline to automatically build, upload and publish extension wheels.
Once your pull request is merged into main branch, a new pull request will be created to update src/index.json automatically.
You only need to update the version information in file setup.py and historical information in file HISTORY.rst in your PR but do not modify src/index.json.

Oct 10 '24 13:10 Sandido

️✔️Azure CLI Extensions Breaking Change Test

️✔️Non Breaking Changes

Oct 10 '24 13:10 azure-client-tools-bot-prd[bot]

Hi @Sandido, Please write the description of changes which can be perceived by customers into HISTORY.rst. If you want to release a new extension version, please update the version in setup.py as well.

Oct 10 '24 13:10 azure-client-tools-bot-prd[bot]

Thank you for your contribution! We will review the pull request and get back to you soon.