feat: add use azapi option for subscription creation.

[luke-taylor]

Overview/summary

Replace this with a brief description of what this Pull Request fixes, changes, etc.

This PR fixes/adds/changes/removes

This allows a user to create a subscription alias and associate it to a management group using entirely the AzApi as opposed to azurerm. This may be preferable when not wanting to assign privileged permissions to the default management group of the tenant.

Breaking changes

No breaking changes.

Testing evidence

Associated to MG.

Not Associated to MG

Local Go TestSubscription*:

As part of this pull request I have

• Checked for duplicate Pull Requests
• Associated it with relevant issues, for tracking and closure.
• Run and make fmt & make docs to format your code and update documentation.
• Created unit and deployment tests and provided evidence.
• Updated relevant and associated documentation.