Print auto inertial values with gz sdf --print --expand-auto-inertials (backport #1422)

[mergify]

🎉 New feature

Closes #1348

Summary

The ability to automatically compute inertial values by setting the //inertial/@auto attribute to true is very convenient, but it is difficult to see what inertial values were computed. This adds a --expand-auto-inertials argument to gz sdf --print to show the auto-computed inertial values in the printed output.

To enable this behavior, a new enum value SAVE_CALCULATION_IN_ELEMENT is added to ConfigureResolveAutoInertials in ParserConfig.hh, and the Link will store auto-computed inertial values directly in its sdf::Element when this configuration is set.

I am seeing a failing test on macOS locally but want to see if it is an issue on other platforms. EDIT: fixed in 2ffda3d.

Test it

• Run INTEGRATION_link_dom to verify the functionality of the Link class with SAVE_CALCULATION_IN_ELEMENT
• Run UNIT_gz_TEST to verify the --expand-auto-inertials parameter to gz sdf --print
• If you build this in a colcon workspace with gz-tools2, then gz sdf --print test/sdf/inertial_stats_auto.sdf with and without --expand-auto-inertials should demonstrate the feature.

Checklist

• Signed all commits for DCO
• Added tests
• Added example and/or tutorial
• Updated documentation (as needed)
• Updated migration guide (as needed)
• Consider updating Python bindings (if the library has them)
• 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

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This is an automatic backport of pull request #1422 done by [Mergify](https://mergify.com).