[GFDL Microphysics 1M] File structure

[FlorianDeconinck]

The file structure chosen for the component is broadly:

• main.py: contain the class
• stencils.py: contain all stencils used in main
• temporaries.py/outputs: gather required quantities

Though nice and clean, it's overly verbose. Re-visit the file structure with an eye for file naming, readability and compactness.