sdf -> usd converter: add joints

[adlarkin]

🎉 New feature

Summary

Adds support for converting joints to their USD representation when parsing a SDF model to USD. Currently, the following joint types are supported:

• revolute
• ball
• fixed
• prismatic

Test it

You can run the unit test that has been added (sdformat/usd/src/sdf_parser/Joint_Sdf2Usd_TEST.cc)

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 #837 (c03c363) into sdf12 (ec11f63) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##            sdf12     #837   +/-   ##
=======================================
  Coverage   90.88%   90.88%           
=======================================
  Files          78       78           
  Lines       12636    12636           
=======================================
  Hits        11484    11484           
  Misses       1152     1152           

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[scpeters]

can you resolve the conflicts?

[ahcorde]

@osrf-jenkins retest this please

[ahcorde]

I pushed some code to address the feedback

[scpeters]

only two minor comments remaining

I still don't get the Y-axis revolute joint issue, but there are todo comments there, so we can come back to it at some point

[adlarkin]

I still don't get the Y-axis revolute joint issue, but there are todo comments there, so we can come back to it at some point

Sounds good, @ahcorde may have some more info about this - I left a comment with some more background/context: #837 (comment)

All other feedback should be addressed now, so this is ready for final review.

[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