Add vtkLinearTransformCellLocator
vtkLinearTransformCellLocator is a cell locator adaptor that can accept any cell locator, e.g. vtkStaticCellLocator, vtkCellLocator, calculate the transformation matrix from the cell locator adaptor's dataset to the given dataset inside BuildLocator, and then use the cell locator and transformation to perform cell locator operations. The transformation matrix is computed using the https://en.wikipedia.org/wiki/Kabsch_algorithm. UseAllPoints allows to compute the transformation using all the points of the dataset (use that when you are not if it's a linear transformation) or 100 sample points (or less if the dataset is smaller) that are chosen every-nth. IsLinearTransformation validates if the dataset is a linear transformation of the cell locator's dataset based on the used points. This functionality is particularly useful for datasets that have time-steps and each timestep is a linear transformation of the first timestep. Finally, the vtkCellLocator, vtkStaticCellLocator, vtkCellTreeLocator, vtkModifiedBSPTree, and vtkLinearTransformCellLocator cell locators also support ShallowCopy now.