CAD11 — different tessellation structures for different kind of entities

There are some different tessellation structures for different kind of entities (geometric and topologic) and some are for both (e.g. EdgeTessellationStruct). Three of the four structs have a obj_ref member with type Object.

Issues: 1. The type Object for obj_ref is too generic. 2. Some of the tessellation structs are for the use with one single interface (ConnectedFaceTessellationStruct -> Body) while some others are used in more than one interface (EdgeTessellationStruct -> Edge, Curve). 3. In some cases the obj_ref member of a single tessellation struct references a geometric entity (Curve, Surface), in others a topologic entity (Edge, Face, Body)

Proposed Solution: For each interface which provides tessellation (has a tessellate() method) there should be one corresponding tessellation struct with a obj_ref member of the type of the interface which generated the struct.

Edge -> EdgeTessellationStruct Face -> FaceTessellationStruct Curve -> CurveTessellationStruct Surface -> SurfaceTessellationStruct Body -> ConnectedFaceTessellationStruct

It would be much clearer that way and the redundancies pretty few.