Merge CAMS2-83 code to main-dev

[heikoklein]

Change Summary

Merging cams-2-83-experiment-2 to main-dav

Related issue number

#1113

Checklist

• Start with a draft-PR
• The PR title is a good summary of the changes
• PR is set to AeroTools and a tentative milestone
• Documentation reflects the changes where applicable
• Tests for the changes exist where applicable
• Tests pass locally
• Tests pass on CI
• At least 1 reviewer is selected
• Make PR ready to review

[lewisblake]

Impressive work getting this PR so far. I know it's taken a lot. Feel free to take my comments in stride. This is a very large PR and introduces a lot of changes that are specific to CAMS2_83 and so generally I think an effort to delineate parts of the code that are specific to cams2-83 would benefit future programmers reading the code. The tests I understand we are not going to worry about for now, but one day I think we should revisit them.

[lewisblake]

Generally methods in this file could benefit from more documentation in the form of docstrings

[charlienegri]

my latest commit breaks the webserver, see test-forecast-day here https://aeroval-test.met.no/charlien/pages/evaluation/?project=cams2-83&experiment=test-forecast-day&station=ALL&parameter=concpm10
basically, the slash in the period strings matters for many parts of the web visualization, so I will revert my last changes and leave it as it was, we can still remove the periodmod line and get filenames written with slashes, but then we will need to tell @AugustinMortier to adapt to this once/if we will deploy this code to production (filenames were written with slashes initially but not anymore now)

[lewisblake]

🌟 🦄 ✨ 🚀