Test cases for improved quality UX

[klakhov]

Motivation and context

Added a couple of test cases for #8865

How has this been tested?

Checklist

• I submit my changes into the develop branch
• [ ] I have created a changelog fragment
• [ ] I have updated the documentation accordingly
• I have added tests to cover my changes
• I have linked related issues (see GitHub docs)
• [ ] I have increased versions of npm packages if it is necessary
  (cvat-canvas,
  cvat-core,
  cvat-data and
  cvat-ui)

License

• I submit my code changes under the same MIT License that covers the project.
  Feel free to contact the maintainers if that's a concern.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 73.89%. Comparing base (4191be3) to head (b8e20d4).

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #8956      +/-   ##
===========================================
- Coverage    73.90%   73.89%   -0.02%     
===========================================
  Files          417      417              
  Lines        44598    44598              
  Branches      4031     4031              
===========================================
- Hits         32960    32954       -6     
- Misses       11638    11644       +6     

Components	Coverage Δ
cvat-ui	78.37% <ø> (-0.03%)	⬇️
cvat-server	70.08% <ø> (ø)

[sonarqubecloud]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud