quality_control: factor out duplicate annotation summary creation logic

[SpecLad]

In addition, remove code creating an unused annotation summary object from generate_report.

Motivation and context

How has this been tested?

Manual testing.

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 #7632 (7c00298) into develop (f513aa1) will decrease coverage by 0.03%.
Report is 1 commits behind head on develop.
The diff coverage is 100.00%.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #7632      +/-   ##
===========================================
- Coverage    83.47%   83.44%   -0.03%     
===========================================
  Files          373      373              
  Lines        39739    39723      -16     
  Branches      3741     3741              
===========================================
- Hits         33171    33147      -24     
- Misses        6568     6576       +8     

Components	Coverage Δ
cvat-ui	79.24% <ø> (-0.05%)	⬇️
cvat-server	87.32% <100.00%> (-0.01%)	⬇️