Add dartpy access to getTransformFrom{Parent|Child}BodyNode()

[chhinze]

For now, those Isometry transformations could only be set, but not read.

1. Add wrapper to add get functionality.
2. Add python unittest to verify, that it is available and returns the same Isometry3.

[Remove this line and describe this pull request. Link to relevant GitHub issues, if any.]

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Before creating a pull request

• Document new methods and classes -> Should this be done for python bindings as well? The pybind11 code does not yet seem to be documented at all.
• Format new code files using clang-format

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• Set version target by selecting a milestone on the right side
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[jslee02]

Should this be done for python bindings as well? The pybind11 code does not yet seem to be documented at all.

Don't worry about this because of what you pointed out. We should add documentation in the future, but it should be fine for now.

[codecov]

Codecov Report

Merging #1377 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #1377   +/-   ##
=======================================
  Coverage   56.97%   56.97%           
=======================================
  Files         366      366           
  Lines       27460    27460           
=======================================
  Hits        15646    15646           
  Misses      11814    11814

[jslee02]

Thanks for your contribution! Looks good to go.

[chhinze]

Awesome. Thank you.