feat: finalize version handling for design class

[smereu]

Description

This PR finalizes the migration of the design class to use mediator service for version handling

Issue linked

Please mention the issue number or describe the problem this pull request addresses.

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

❌ Patch coverage is 94.44444% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 95.15%. Comparing base (f58972a) to head (550a901).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
...rc/ansys/geometry/core/_grpc/_services/v1/beams.py	66.66%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2323      +/-   ##
==========================================
- Coverage   95.16%   95.15%   -0.02%     
==========================================
  Files         169      169              
  Lines       11180    11194      +14     
==========================================
+ Hits        10640    10652      +12     
- Misses        540      542       +2     

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[RobPasMue]

Requesting a few changes - thanks for taking the time @smereu !!

[smereu]

@RobPasMue I should marked this as draft last night but I am glad you reviewed it. I will make the changes today!

[RobPasMue]

@RobPasMue I should marked this as draft last night but I am glad you reviewed it. I will make the changes today!

No problem =) thanks @smereu !!

[RobPasMue]

LGTM!