[BUG] IfcSphere in IfcShapeRepresentation not supported

[christophKaiser]

Describe the bug
If an IfcSphere is defined as follwing, the sphere is not displayed in the rendering of the ifc file. An appropriate error message appears in the output window, which tells the entity is not supported.

IfcProductDefinitionsShape
  IfcShapeRepresentation
    IfcSphere

However, other viewers do support this structure, like FreeCAD or BIMcollab.

Screen shot
OIP:

FreeCAD:

[Stefan Jaud]

Expand RepresentationConverter::convertIfcGeometricRepresentationItem appropriately for IfcCsgPrimitive3D and call SolidModelConverter::convertIfcCsgPrimitive3D. Should work then.

[christophKaiser]

Thanks. I already have the code changes - just have to do a little bit of cosmetics and put them into nice commits.