Add Arpege Global Model processing

[jacobbieker]

We want to use multiple NWPs for our models. We need to process the raw data we've downloaded/will continue to download.

Arpege has a 0.5 degree resolution globally, or around 55km, while the EU version has a resolution of 11km.

Detailed Description

Context

Multiple NWPs seem important for making our models perform the best.

Possible Implementation

In the NWP consumer.