chore: Remove top navigation beta code

[timogasda]

Description

This PR removes the top navigation beta code, which has been replaced by the stable top navigation component in 2022.

It also removes the "idea" of beta components (listBetaVersions), since this was the only beta component and we currently no plans to bring this idea back.

Related links, issue #, if available: n/a

How has this been tested?

Review checklist

The following items are to be evaluated by the author(s) and the reviewer(s).

Correctness

• Changes include appropriate documentation updates.
• Changes are backward-compatible if not indicated, see CONTRIBUTING.md.
• Changes do not include unsupported browser features, see CONTRIBUTING.md.
• Changes were manually tested for accessibility, see accessibility guidelines.

Security

• If the code handles URLs: all URLs are validated through the checkSafeUrl function.

Testing

• Changes are covered with new/existing unit tests?
• Changes are covered with new/existing integration tests?

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 96.92%. Comparing base (8fa9df2) to head (a229124).
⚠️ Report is 26 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3605      +/-   ##
==========================================
+ Coverage   96.62%   96.92%   +0.30%     
==========================================
  Files         818      812       -6     
  Lines       23799    23565     -234     
  Branches     8354     8177     -177     
==========================================
- Hits        22996    22841     -155     
+ Misses        749      674      -75     
+ Partials       54       50       -4     

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[avinashbot]

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