[examples] Feature/pnm non creeping upscaling

What this MR does / why does DuMux need it:

Upscaling non-creeping flow (#997 (closed))

Example: modelling creeping and non-creeping flow using the pore network model and then upscaling to show the impact of pore scale phenomena on the macroscale behavior.

Notes for the reviewer

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• does the new code follow the style guide?
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• are newly introduced or modified physical values/functions backed up with a scientific reference (including doi) in the docs?
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