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 73.43%. Comparing base (59fe97f) to head (3ed23e9).

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #9026      +/-   ##
===========================================
- Coverage    73.43%   73.43%   -0.01%     
===========================================
  Files          419      419              
  Lines        44351    44356       +5     
  Branches      3875     3875              
===========================================
+ Hits         32570    32571       +1     
- Misses       11781    11785       +4     

Components	Coverage Δ
cvat-ui	77.40% <ø> (-0.04%)	⬇️
cvat-server	70.13% <48.48%> (+0.01%)	⬆️

[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