Workload identity support (#2126)

* WIP: support for workload identity

* WIP: bugfixes to support WI

* Added support for Workload Identity

* Added missing flag

* Refactoring and typo

* Updated CHANGELOG.md

* Updated docs

* Updated changelog

* Improved readability and fixed codeclimate issues

* Update CHANGELOG.md

Co-authored-by: Joel Speed <Joel.speed@hotmail.co.uk>

* Fixed if statement

* Apply suggestions from code review

Co-authored-by: Jan Larwig <jan@larwig.com>

* Cleanup

* Removed target principal

* Removed references to target principal

* Added docs

* Fixed header anchor linking

* Update auth.md

* Updated generated code

* Improved code

* Fixed tests

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Co-authored-by: Joel Speed <Joel.speed@hotmail.co.uk>
Co-authored-by: Jan Larwig <jan@larwig.com>