Refactor quality reports

[zhiltsov-max]

Motivation and context

An extract from #8953

• Symbols in quality report computation are made public
• Added some type annotations
• Updated quality computation rq job status handling to include the scheduled status as well

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)

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

Attention: Patch coverage is 48.48485% with 51 lines in your changes missing coverage. Please review.

Project coverage is 73.75%. Comparing base (89c4af5) to head (207965b).
Report is 1 commits behind head on develop.

Additional details and impacted files

@@           Coverage Diff            @@
##           develop    #9026   +/-   ##
========================================
  Coverage    73.74%   73.75%           
========================================
  Files          428      428           
  Lines        44502    44504    +2     
  Branches      3877     3877           
========================================
+ Hits         32820    32822    +2     
  Misses       11682    11682           

Components	Coverage Δ
cvat-ui	77.44% <ø> (-0.03%)	⬇️
cvat-server	70.70% <48.48%> (+0.02%)	⬆️

[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