feat(Azure): add new check for private DNS zones

[johannes-engler-mw]

Description

Adds #1454 .

This PR adds an assertion helper for Azure Private DNS Zones.

TODOs

Read the Gruntwork contribution guidelines.

• Update the docs.
• Run the relevant tests successfully, including pre-commit checks.
• Ensure any 3rd party code adheres with our license policy or delete this line if its not applicable.
• Include release notes. If this PR is backward incompatible, include a migration guide.

Release Notes (draft)

Added support for Azure Private DNS Zones assertion helpers.

[johannes-engler-mw]

@denis256 I have implemented your comments, please review.

[johannes-engler-mw]

@denis256 Could you have a look?

[james03160927]

Hi @johannes-engler-mw, I can help to trigger relevant tests for this change.
Also, it seems like you need to resolve conflicts for some of the recent commits.

[johannes-engler-mw]

Hi @james03160927, i have fixed the merge conflict. Please retrigger the tests.

[james03160927]

Hi @johannes-engler-mw, can you modify the title to remove WIP since it's already being reviewed?
Also, did you confirm the test is passing with your change (the test you created in this PR?)

[johannes-engler-mw]

@james03160927 I have run my new tests and they where successful.

[james03160927]

LGTM. Can you update the branch with the latest change merged in main? You can just click the button.