Add Lanczos3 interpolation

[zdila]

I use ndarray with codex-crafted Lanczos3 interpolation and I whink it would be great if it could be maintaned in some public library like this one 🙂

Feel free to take inspiration from https://github.com/FreemapSlovakia/hillshader/blob/bb61e8f580ccb99c0db31e3aebe8407ba55b1510/laz2dem/src/lanczos.rs

Or I can try to make PR. What do you think?

[jonasBoss]

You can work on a PR.
Take a look at the Interp2DStrategy and Interp2DStrategyBuilder traits. You will need to implement these to add your interpolation strategy.