[Asset Inventory][Azure] Add Acitive Directory fetcher to fetch Service Principals

[kubasobon]

Summary of your changes

This PR adds an Active Directory fetcher and fetchers Azure Service Principals. It utilizes microsoftgraph/msgraph-sdk-go, since this Active Directory API is not exposed in the SDK we've been using so far. This is the recommended approach.

Screenshot/Data

Related Issues

Closes https://github.com/elastic/security-team/issues/10161

Checklist

• I have added tests that prove my fix is effective or that my feature works
• I have added the necessary README/documentation (if appropriate)

[mergify]

This pull request does not have a backport label. Could you fix it @kubasobon? 🙏
To fixup this pull request, you need to add the backport labels for the needed
branches, such as:

• backport-v./d./d./d is the label to automatically backport to the 8./d branch. /d is the digit
  NOTE: backport-v8.x has been added to help with the transition to the new branch 8.x.

[mergify]

This pull request is now in conflicts. Could you fix it? 🙏
To fixup this pull request, you can check out it locally. See documentation: https://help.github.com/articles/checking-out-pull-requests-locally/

git fetch upstream
git checkout -b ast-inv-azure-principals upstream/ast-inv-azure-principals
git merge upstream/main
git push upstream ast-inv-azure-principals

[mergify]

This pull request is now in conflicts. Could you fix it? 🙏
To fixup this pull request, you can check out it locally. See documentation: https://help.github.com/articles/checking-out-pull-requests-locally/

git fetch upstream
git checkout -b ast-inv-azure-principals upstream/ast-inv-azure-principals
git merge upstream/main
git push upstream ast-inv-azure-principals

[mergify]

This pull request is now in conflicts. Could you fix it? 🙏
To fixup this pull request, you can check out it locally. See documentation: https://help.github.com/articles/checking-out-pull-requests-locally/

git fetch upstream
git checkout -b ast-inv-azure-principals upstream/ast-inv-azure-principals
git merge upstream/main
git push upstream ast-inv-azure-principals

[romulets]

shouldn't we return the error if principals are not returned?

[kubasobon]

This is a log, because we might still get some resources. The pagination failed, but items slice has been populated. We try to get the best scenario for us - getting data, even if incomplete.

[romulets]

I agree. It's just that we don't check if there was indeed any item or not. But also I don't have a good argument to bring the error up if the items is empty and error exist. In practice an error will be logged anyway

[kubasobon]

@romulets Please take another look