refactor dwc2parquet job into separate repository

[jhpoelen]

suggest include namespace prefixes as used here:
https://github.com/iDigBio/idb-backend/blob/master/idb/helpers/fieldnames.py

[mjcollin]

Prefixes are ok but I'd like to ask that column names not include ":" or ".". See bio-guoda/guoda-datasets#1

I've been unable to find a trick for working with ":" in column names from the py4j version that ships with Spark 2.0.

[jhpoelen]

@mjcollin ":" and "." are definitely a source of funkiness. Hopefully, we can figure out a way to deal with this without having to change too much in existing jobs.