Plane geometry for MeshClipper

[gunney1]

Summary

• This PR is a feature
• It does the following:
  • Add Plane3DClipper, the 3D plane geometry implemenation for MeshClipper
  • Add test for Plane3DClipper

The framework code for MeshClipper uses geometry-specific implenentations of the MeshClipperStrategy class. This PR implements the 3D plane geometry through that strategy class.

[Arlie-Capps]

Please update the Summary to say "This PR implements the plane geometry," rather than the sphere.

[gunney1]

Please update the Summary to say "This PR implements the plane geometry," rather than the sphere.

Oops! Thank you.