Regrid NWP inputs

[dfulu]

Pull Request

Description

The current NWP data is on a different grid than was trained on. See openclimatefix/nwp-consumer#26 for more discussion.

This pull request adds a function to regrid the NWP if the data is on a different grid than the training data. This is done eagerly and saved to disk before the prediction pipeline is run.

How Has This Been Tested?

Tested the regridding function locally to make sure it produces sensible looking results

Checklist:

• [x] My code follows OCF's coding style guidelines
• [x] I have performed a self-review of my own code
• [x] I have made corresponding changes to the documentation
• [x] I have added tests that prove my fix is effective or that my feature works
• [x] I have checked my code and corrected any misspellings