chore: cleanup conversions module and remaining imports

[RobPasMue]

Description

Final cleanup and review on #1817

Issue linked

Closes #1817

Checklist

• I have tested my changes locally.
• I have added necessary documentation or updated existing documentation.
• I have followed the coding style guidelines of this project.
• I have added appropriate unit tests.
• I have reviewed my changes before submitting this pull request.
• I have linked the issue or issues that are solved to the PR if any.
• I have assigned this PR to myself.
• I have added the minimum version decorator to any new backend method implemented.
• I have made sure that the title of my PR follows Conventional commits style (e.g. feat: extrude circle to cylinder)

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 95.35%. Comparing base (d672d72) to head (58978b6).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2332      +/-   ##
==========================================
+ Coverage   95.22%   95.35%   +0.13%     
==========================================
  Files         169      168       -1     
  Lines       11236    11067     -169     
==========================================
- Hits        10699    10553     -146     
+ Misses        537      514      -23     

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