feat: add a loading animation to the osv iframe

[WeizhouRen]

Added a spinner indicating iframe is loading. Fixes #1524

animation_demo.mov

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[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 64.58%. Comparing base (91f56a9) to head (2bb60ba).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1661      +/-   ##
==========================================
+ Coverage   64.56%   64.58%   +0.01%     
==========================================
  Files         155      155              
  Lines       15997    15997              
==========================================
+ Hits        10329    10332       +3     
+ Misses       4984     4982       -2     
+ Partials      684      683       -1     

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[hogo6002]

Thanks for contributing!!! Could you please run ./scripts/run_formatters.sh locally to fix the formatting issue?

[hogo6002]

Thanks!