Update AuthenticationFilter proposal

[shaun-nx]

Proposed changes

This change updates the AuthenticationFilter proposal.

Changes made:

• Update API validation
• Removal of OnFailure configuration
• Add additional details on functional testing

Details related to AuthFailure are captured in the Stretch Goals section

Closes #4423

Checklist

Before creating a PR, run through this checklist and mark each as complete.

• I have read the CONTRIBUTING doc
• I have added tests that prove my fix is effective or that my feature works
• I have checked that all unit tests pass after adding my changes
• I have updated necessary documentation
• I have rebased my branch onto main
• I will ensure my PR is targeting the main branch and pulling from my branch from my own fork

Release notes

If this PR introduces a change that affects users and needs to be mentioned in the release notes,
please add a brief note that summarizes the change.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 86.34%. Comparing base (2fcba62) to head (658f904).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4424      +/-   ##
==========================================
- Coverage   86.36%   86.34%   -0.03%     
==========================================
  Files         132      132              
  Lines       14849    14849              
  Branches       35       35              
==========================================
- Hits        12825    12822       -3     
- Misses       1805     1807       +2     
- Partials      219      220       +1     

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[Copilot]

Pull request overview

This PR updates the AuthenticationFilter proposal by refining the API design, removing the OnFailure configuration from the main spec, and enhancing documentation quality. The changes move AuthFailure customization to stretch goals while improving clarity throughout the proposal.

Key Changes:

• Removed OnFailure configuration from BasicAuth and JWTAuth specs, relocating it to stretch goals
• Enhanced functional testing section with detailed test case scenarios
• Fixed numerous spelling and grammatical errors throughout the document

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[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 1 comment.

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Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated no new comments.

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[salonichf5]

There is a couple of places with typos for marked but looks good to me, approving it