feat: added visualisation for CircleFact; added Torus- and ConeGenerator

Added scripts for generating circle-, cone and torus shaped meshes Added fact visualisation for CircleFact as torus Moved CircleSegmentGenerator under MeshGenerator Added WrapperClasses for the new Facts Added new Prefabs and new images for the new facts Adjusted the PointerGadget Added a new Gadget to compare circles Added some more functionalities to Scroll.cs to better extract information out of SOMDoc-terms