feat: v1 implementation of design stub

[umutsoysalansys]

Description

This PR is aiming to implement open file, get active, read assembly path in V1 so we can run a basic test like open a design and verifiy number of bodies.

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

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 92.69%. Comparing base (b9faa09) to head (27ac458).
⚠️ Report is 3 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2396   +/-   ##
=======================================
  Coverage   92.69%   92.69%           
=======================================
  Files         169      169           
  Lines       11704    11708    +4     
=======================================
+ Hits        10849    10853    +4     
  Misses        855      855           

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