Uses the current path as a clipping region. This region clips subsequent Fill() and Stroke() operations.
For performance reasons, this only works for Painter2D instances created with "new Painter2D()" to be eventually saved
to a VectorImage using SaveToVectorImage. This will not work with Painter2D attached to a
MeshGenerationContext.
Note that the clipped shapes will not have antialiased edges since the clipping path is applied by doing a per-triangle
clipping process. Use PopClip() to remove the most recently added clipping region.