Description

Follow up issue for #480. Further restructuring.

There are still a lot of x fields that can be optimized. The field x.S could be more self explanatory (@HenkMutsaerts suggested to use x.stats). We could use a single field for directories and paths (x.dir) and use subfields for dataset specific and exploreasl specific paths (instead of x.D and x.P) or we could merge x.dir and x.D at least (attention: x.dir contains symbolic fields). We also thought about moving some of the module specific variables to dedicated fields (x.modules.import, x.modules.asl, etc.).

Requirements

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How to test

Optional: insert description about how to test the code changes here

Release notes

IGNORE THIS, DONE in #717.