chore: Fix code reuse between app layout and alert/flashbar runtime API

[just-boris]

Description

Make sure that when we refactor something for app layout, we do not break flashbar

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

How has this been tested?

Locally (visited app layout and flashbar dev pages) + all tests in dry-run

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?

---

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[just-boris]

This is the problematic code. It was unintentionally included into the flashbar runtime API too, which is unexpected

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 96.25%. Comparing base (02a8ba3) to head (a0c9a56).
Report is 3 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2963   +/-   ##
=======================================
  Coverage   96.25%   96.25%           
=======================================
  Files         769      768    -1     
  Lines       21736    21742    +6     
  Branches     7430     7430           
=======================================
+ Hits        20921    20927    +6     
  Misses        807      807           
  Partials        8        8           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.