Add test to check "Remove underlying pixels" tool

[novda]

Motivation and context

Testing "Remove underlying pixels" tool with coverage case in #7637

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]

Codecov Report

Merging #7684 (cd8bedc) into develop (087a7ea) will decrease coverage by 0.03%.
Report is 7 commits behind head on develop.
The diff coverage is n/a.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #7684      +/-   ##
===========================================
- Coverage    83.40%   83.37%   -0.03%     
===========================================
  Files          373      373              
  Lines        39722    39744      +22     
  Branches      3741     3745       +4     
===========================================
+ Hits         33130    33137       +7     
- Misses        6592     6607      +15     

Components	Coverage Δ
cvat-ui	79.19% <ø> (-0.05%)	⬇️
cvat-server	87.24% <ø> (-0.01%)	⬇️