Support for Azure US Gov, Azure China (Sovereign Clouds) in ALZ

Today in ALZ we do not provide full support for Azure US Gov or Azure China and other Microsoft Azure Sovereign Clouds (not to be confused with [SLZ](https://aka.ms/sovereign/slz) as we do support this).

### Why?

We in the ALZ team, do not have access to test tenants and subscriptions in these clouds today to be able to automate our testing here which is a mandatory requirement we have for enabling support for a cloud. Manual testing is not an option here due to the velocity of changes we make.

### Does this mean it doesn't work at all?

No, we know it can work with some tweaks, mainly to policy definitions, initiatives and assignments that are not available in these other clouds. Once removed from your code to deploy ALZ, you can deploy ALZ just fine.

But we don't maintain a list of the required changes today as again, would require manual testing and access which we do not have 😢

> If you do have access and have information on what needs changing, please comment on this issue to share with the community

### Will ALZ ever support these clouds?

We would love to and are constantly working with teams to try and get access to these clouds internally in secure and compliant way, inline with our processes, but this is a very long running issue and we do not expect to have support for these, or access, anytime soon.

The issue names no files, tests, or entry points. Start by identifying the policy definitions, initiatives, and assignments that differ across Azure sovereign clouds, then determine whether suitable test tenants and subscriptions are available. Done would require documented required changes and automated validation for the supported clouds.

Written by the indexing model from the issue text.