Fast healpix convolution - timeboxed evaluation

[tjhunter]

NVidia has some code
TODO details

[sophie-xhonneux]

Some relevant repo/packages:

• https://nvlabs.github.io/earth2grid/tutorials/healpix.html
• https://docs.nvidia.com/deeplearning/physicsnemo/physicsnemo-core/api/physicsnemo.models.html#module-physicsnemo.models.dlwp.dlwp
• https://github.com/NVlabs/cuHPX