`az arcvmware onboard` command to run the onboarding steps after az-cli install

[nascarsayan]

---

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

Related command

General Guidelines

• [ ] Have you run azdev style <YOUR_EXT> locally? (pip install azdev required)
• [ ] Have you run python scripts/ci/test_index.py -q locally? (pip install wheel==0.30.0 required)

For new extensions:

• [ ] 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.

[azure-client-tools-bot-prd[bot]]

⚠️Azure CLI Extensions Breaking Change Test

⚠️connectedvmware

rule	cmd_name	rule_message	suggest_message
⚠️ 1001 - CmdAdd	connectedvmware onboard	cmd connectedvmware onboard added

[azure-client-tools-bot-prd[bot]]

Hi @nascarsayan, 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.

[yonzhan]

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