Interpolation refactoring
This is among other small things a refactoring of the interpolation
- Make textures less special (now subclasses of interpolator)
- Remove
TextureCache
- (Ab-) use finite differences to enable spatial derivatives of interpolators
- enable code to use https://github.com/theHamsta/CubicInterpolationCUDA (not included into pystencils, not even as a submodule)
I can use it to transform Lenna and get gradients with Torch wrt. to image content, x-translation, y-translation