Scaling is applied to the normals descriptor in SimilarityTransformation class

[simonpierredeschenes]

In the inPlaceCompute function of SimilarityTransformation, in TransformationsImpl.cpp, the whole top left submatrix of the TransformationParameters is applied to the normals descriptor. However, if this transformation contains non-uniform scaling for the different axes, this will cause issues in a lot of different places in libpointmatcher.