Create functional tests for Azure Sign Tool

[james-garriss]

💡 Summary

AST is a critical tool, but as it's external to our code, testing it should be a functional test instead of a unit test. This issue should write one or more functional tests for AST and added to the nightly functional tests.

Motivation and context

We need to know if/when AST is not working.

Acceptance criteria

How do we know when this work is done?

• Good functional tests are running regularly.