Add support for Pushed Authorization Requests

[frederikprijck]

Changes

Adds support for Pushed Authorization Requests.

References

https://www.rfc-editor.org/rfc/rfc9126.html

Testing

Please describe how this can be tested by reviewers. Be specific about anything not tested and reasons why. If this library has unit and/or integration testing, tests should be added for new functionality and existing tests should complete without errors.

• [x] This change adds unit test coverage
• [x] This change adds integration test coverage

Checklist

• [x] I have read the Auth0 general contribution guidelines
• [x] I have read the Auth0 Code of Conduct
• [x] All existing and new tests complete without errors