[PS] Migrate Orbital module to autorest v4

[JoyerJin]

Description

Mandatory Checklist

• Please choose the target release of Azure PowerShell. (⚠️Target release is a different concept from API readiness. Please click below links for details.)

  • General release
  • Public preview
  • Private preview
  • Engineering build
  • No need for a release

• Check this box to confirm: I have read the Submitting Changes section of CONTRIBUTING.md and reviewed the following information:

• SHOULD update ChangeLog.md file(s) appropriately
  • For SDK-based development mode, update src/{{SERVICE}}/{{SERVICE}}/ChangeLog.md.
    • A snippet outlining the change(s) made in the PR should be written under the ## Upcoming Release header in the past tense.
  • For autorest-based development mode, include the changelog in the PR description.
  • Should not change ChangeLog.md if no new release is required, such as fixing test case only.
• SHOULD regenerate markdown help files if there is cmdlet API change. Instruction
• SHOULD have proper test coverage for changes in pull request.
• SHOULD NOT adjust version of module manually in pull request

[azure-client-tools-bot-prd]

Thanks for your contribution! The pull request validation has started. Please revisit this comment for updated status.

[dolauli]

Hi @JoyerJin,
Please also update the change log with something as below:

Regenerate the module using the latest v4 generator to incorporate the new features added in the v4 generator.

[github-actions]

This PR was labeled "needs-revision" because it has unresolved review comments or CI failures.
Please resolve all open review comments and make sure all CI checks are green. Refer to our guide to troubleshoot common CI failures.

[JoyerJin]

Thank you, if this is ready for release, I will add the change log.

[dolauli]

LGTM