chore: Add visual regression testing

[jperals]

Description

Issue: D417180663

How has this been tested?

• New items are added to the list of PR checks. For now they are not required
• Allure report is added to the "Deployments" section below
• Stress-tested running all 102 test suites in this draft PR (currently only 2 test suites are run). Thanks to the raw screenshot comparison approach (more about that in this PR's code) and high sharding, the total run time of the new workflow with all tests is slightly below the existing dry run workflow (23 vs 24 minutes) and it should be possible to refine this further

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 97.57%. Comparing base (7f6f93b) to head (fa8c574).
⚠️ Report is 4 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #4509   +/-   ##
=======================================
  Coverage   97.57%   97.57%           
=======================================
  Files         948      948           
  Lines       30495    30507   +12     
  Branches    11154    11164   +10     
=======================================
+ Hits        29755    29767   +12     
+ Misses        733      693   -40     
- Partials        7       47   +40     

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[jperals]

Needed for the internal tests to consume the test definitions, which are going to live in this package.

[georgylobko]

isn't it outdated?

[jperals]

Updated to 24 (current LTS), in both deploy.yml and visual-regression.yml, which are the only files in this repo that use this parameter.