feat: introduce authz_permission_required decorator

[dwong2708]

Resolves openedx/openedx-authz#200

Description

This PR introduces a new decorator to enforce permissions using the new AuthZ system and applies it to the Course Quality and Course Validations endpoints.

The decorator centralizes the authorization logic for course authoring APIs by checking permissions through the AuthZ service, with an optional fallback to the legacy permission system during the migration period.

As part of implementing the new permissions for the Checklist section of the course, the decorator is now applied to the following endpoints:

• Course Quality API
• Course Validations API

This ensures that access to checklist-related functionality is properly controlled by the new permission model.

Changes

• Added a new authz_permission_required decorator to enforce AuthZ permissions.
• Implemented support for extracting the course key from different view argument patterns (function views, class-based views, and DRF routes).
• Applied the decorator to:
  • Course Quality endpoint
  • Course Validations endpoint
• Maintained optional fallback to the legacy permission check during the transition period.

Testing

• Added tests for the decorator behavior.
• Verified that:
  • Authorized users can access the endpoints.
  • Unauthorized users receive a 403 response.
  • Legacy permission fallback works as expected.

Context

This change is part of the work to support RBAC/AuthZ permissions for the Checklist section in course authoring.

[openedx-webhooks]

Thanks for the pull request, @dwong2708!

This repository is currently maintained by @openedx/wg-maintenance-openedx-platform.

Once you've gone through the following steps feel free to tag them in a comment and let them know that your changes are ready for engineering review.

🔘 Get product approval

If you haven't already, check this list to see if your contribution needs to go through the product review process.

• If it does, you'll need to submit a product proposal for your contribution, and have it reviewed by the Product Working Group.
  • This process (including the steps you'll need to take) is documented here.
• If it doesn't, simply proceed with the next step.

🔘 Provide context

To help your reviewers and other members of the community understand the purpose and larger context of your changes, feel free to add as much of the following information to the PR description as you can:

• Dependencies

  This PR must be merged before / after / at the same time as ...

• Blockers

  This PR is waiting for OEP-1234 to be accepted.

• Timeline information

  This PR must be merged by XX date because ...

• Partner information

  This is for a course on edx.org.

• Supporting documentation
• Relevant Open edX discussion forum threads

🔘 Get a green build

If one or more checks are failing, continue working on your changes until this is no longer the case and your build turns green.

Details

---

Where can I find more information?

If you'd like to get more details on all aspects of the review process for open source pull requests (OSPRs), check out the following resources:

• Overview of Review Process for Community Contributions
• Pull Request Status Guide
• Making changes to your pull request

When can I expect my changes to be merged?

Our goal is to get community contributions seen and reviewed as efficiently as possible.

However, the amount of time that it takes to review and merge a PR can vary significantly based on factors such as:

• The size and impact of the changes that it introduces
• The need for product review
• Maintenance status of the parent repository

💡 As a result it may take up to several weeks or months to complete a review and merge your PR.

[rodmgwgu]

Looking good, just one logic change and some minor comments.

[rodmgwgu]

Looks good, thanks! Tested in my local and works as expected.