Add resection Bezier deformable widget

[RafaelPalomar]

The aim of this is the creation of a resection widget based on Bezier deformable surfaces. We are basing this development on the pluggable-markups branch. For an example of the working demo of the NorMIT-Plan, see the following video:

[NorMIT-Plan demo](https://youtu.be/7M3DULQp81k

The part to implement here is only the deformable Bezier surface. The initialization part (slicing contour) is considered in #5. Technical details are given in this paper. There is code available in NorMIT-Plan. Note that some parts of the code cannot be integrated directly, since they are not using modern infrastructure in 3D Slicer (e.g., Markups). Suggestion of sub-tasks and order:

• Add a basic vtkMRMLMarkupsNode (this is just to support the development).
• Transfer the vtkBezierSurfaceSource code to the Slicer module (this should not require any adaptation).
• Create the 3D widget representation. (Look of the widget).
• Create the 3D widget. (Interaction of the widget).
• Adding unit tests.
• Adding integration tests.
• Create the 2D widget representation. (Look of the widget).
• Create the 2D widget. (Interaction of the widget).

One might have to register a dummy widget and markups in order to see the results on the screen. For a working example look at the line widget already existing line-widget.