USD to SDF: Added some world plugins

[ahcorde]

Signed-off-by: ahcorde [email protected]

🎉 New feature

Summary

USD to SDF: Added some world plugins

Checklist

• Signed all commits for DCO
• Added tests
• Added example and/or tutorial
• Updated documentation (as needed)
• Updated migration guide (as needed)
• codecheck passed (See contributing)
• All tests passed (See test coverage)
• While waiting for a review on your PR, please help review another open pull request to support the maintainers

Note to maintainers: Remember to use Squash-Merge and edit the commit message to match the pull request summary while retaining Signed-off-by messages.

[codecov-commenter]

Codecov Report

Merging #901 (df8d898) into sdf12 (425985f) will increase coverage by 0.01%.
The diff coverage is 100.00%.

❗ Current head df8d898 differs from pull request most recent head e2a45e4. Consider uploading reports for the commit e2a45e4 to get more accurate results

@@            Coverage Diff             @@
##            sdf12     #901      +/-   ##
==========================================
+ Coverage   88.11%   88.12%   +0.01%     
==========================================
  Files         100      100              
  Lines       14651    14668      +17     
==========================================
+ Hits        12909    12926      +17     
  Misses       1742     1742              

Impacted Files	Coverage Δ
usd/src/usd_parser/USDWorld.cc	80.43% <100.00%> (+10.43%)	⬆️
usd/src/sdf_parser/Link.cc	61.84% <0.00%> (ø)
usd/src/UsdTestUtils.hh	99.00% <0.00%> (+<0.01%)	⬆️

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[osrf-triage]

This pull request has been mentioned on Gazebo Community. There might be relevant details there:

https://community.gazebosim.org/t/new-ignition-releases-2022-04-13-fortress-edifice/1367/1