Add geometries that take a path as input

[jared-hughes]

• Extrude; maybe name "Extrusion"
• Shape
• Lathe aka "Revolve"
  • always revolves about y-axis.

Extrusion and Shape take a 2-d Path as input. This could simple be a list of line segments, but it could also support Quadratic curves and Cubic Bezier curves. Simplest option would be to use splineThru to get a smooth cubic spline through the list of points.

Note: Desmos points are not currently exposed in the API, so this would require a 2d point function similar to Vector3.

Lathe takes a list of points for some reason and does not support paths.

[jared-hughes]

See #40 for some ideas about obtaining generated segments and functions from the Calc object