fix: Fix popover in split panel leaking outside of the split panel container

[timogasda]

Description

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?

---

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

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 95.40%. Comparing base (10971ef) to head (8b773a9).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2211      +/-   ##
==========================================
- Coverage   95.41%   95.40%   -0.01%     
==========================================
  Files         696      696              
  Lines       18667    18667              
  Branches     6206     6246      +40     
==========================================
- Hits        17811    17810       -1     
- Misses        803      850      +47     
+ Partials       53        7      -46     

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.