Description

KeyVault will update their API design of security domain import/export to be asynchronous.
This PR make sure our cmdlet won't break when the API change takes place.

Change list:

• Support both sync and async API design
• Improved some error handling to throw AzPS*Exception
• Supported cancelling cmdlet execution by ctrl-C
• Added debug log

Testing:
I tested on public cloud for the old API. Will ask KeyVault team's help to test in dogfood.

Checklist

• I have read the Submitting Changes section of CONTRIBUTING.md
• The title of the PR is clear and informative
• The appropriate ChangeLog.md file(s) has been updated:
  • For any service, the ChangeLog.md file can be found at src/{{SERVICE}}/{{SERVICE}}/ChangeLog.md
  • A snippet outlining the change(s) made in the PR should be written under the ## Upcoming Release header -- no new version header should be added
• The PR does not introduce breaking changes
• If applicable, the changes made in the PR have proper test coverage
• For public API changes to cmdlets:
  • a cmdlet design review was approved for the changes in this repository (Microsoft internal only)
    • {Please put the link here}
  • the markdown help files have been regenerated using the commands listed here