Add usda and usdc file format for viewer3D

[servantftransperfect]

This pull request adds support for the .usda and .usdc 3D file formats throughout the codebase, ensuring they are recognized as valid 3D extensions in both the backend and the UI, and are covered by tests.

3D File Format Support:

• Added .usda and .usdc to the list of valid 3D file extensions in Attribute so they are recognized as supported formats.
• Updated the supported extensions in the 3D viewer settings (Viewer3DSettings.qml) to include .usda and .usdc, ensuring these formats appear as options in the UI.
• Modified the media loader (MediaLoader.qml) to handle .usda and .usdc files, allowing them to be loaded in the viewer.

Testing:

• Extended the test cases in tests/test_attributes.py to include .usda and .usdc as valid 3D extensions, ensuring the new formats are properly validated.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
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

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 83.35%. Comparing base (2ed841d) to head (d2e0a5b).
⚠️ Report is 26 commits behind head on develop.
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@           Coverage Diff            @@
##           develop    #3083   +/-   ##
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  Coverage    83.35%   83.35%           
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  Files           73       73           
  Lines         9890     9890           
========================================
  Hits          8244     8244           
  Misses        1646     1646           

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