This is the first commit to generate correct, readable Parquet files.

This also further refines the YAML writing for processes,
and the base interfaces.

Merge branch '222-distinguish-between-alternative-interaction-processes-and-competing-processes' into 'master'

Resolve "Distinguish between alternative interaction processes and competing processes"

Closes #222 and #162

See merge request !269

Add benchmark processor and dummy processors

See merge request AirShowerPhysics/corsika!253