Itk-thickness3d

What's Changed
* COMP: Modules need updated version of ITK by hjmjohnson in https://github.com/InsightSoftwareConsortium/ITKThickness3D/pull/42
* COMP: Remove inclusion of .hxx files as headers by hjmjohnson in https://github.com/InsightSoftwareConsortium/ITKThickness3D/pull/41
* ENH: Bump ITK and change http to https by tbirdso in https://github.com/InsightSoftwareConsortium/ITKThickness3D/pull/45
* ENH: Update CI for ITK 5.3.0 by thewtex in https://github.com/InsightSoftwareConsortium/ITKThickness3D/pull/48

New Contributors
* tbirdso made their first contribution in https://github.com/InsightSoftwareConsortium/ITKThickness3D/pull/45

**Full Changelog**: https://github.com/InsightSoftwareConsortium/ITKThickness3D/compare/v5.2.0...v5.3.0

*ITKThickness3D is now part of the [InsightSoftwareConsortium](https://github.com/InsightSoftwareConsortium)*

- The binary thinning filter was merged into the Thickness3D module:
**[`itk::BinaryThinningImageFilter3D<TInputImage, TOutputImage>`](https://github.com/InsightSoftwareConsortium/ITKThickness3D/blob/master/include/itkBinaryThinningImageFilter3D.h)**: Compute the 3D [skeleton](http://hdl.handle.net/1926/1292)
of the input image..
- Tests have been improved and are now quantitative
- Source code have been re-styled to match ITK standards

> This version is still in beta since ITK 5.0 hasn't been released and some features are still missing (e.g. local thickness transform)

**ITKThickness3D Alpha 1 is ready for testing!**

ITKThickness3D brings tools for 3D thickness evaluation.
This the first in a stage of the module featuring introducing a new composite filter:
**[`itk::MedialThicknessImageFilter3D<TInputImage, TOutputImage>`](https://github.com/InsightSoftwareConsortium/ITKThickness3D/blob/master/include/itkMedialThicknessImageFilter3D.h)**: The [distance](https://itk.org/Doxygen/html/classitk_1_1SignedMaurerDistanceMapImageFilter.html) to the outside along the medial axis.