Add eTeryt designators if applicable

[not7cd]

Motivation

Italian ministry shares its data here: https://github.com/pcm-dpc/COVID-19
In region files, they use region codes next to region names.

Poland has a system for unique ids for cities and administration units.
http://eteryt.stat.gov.pl/eTeryt/

Because in Poland there are cities with non-unique names, adding such ids should help with further data manipulation.

Proposed change

Add python modules with CLI capability to seamlessly integrate into the current environment.
They should:

• Modify files only if there is missing data.
• Not modify rows if unique id was not found for a given row.
• Could be run over files multiple times resulting in exactly the same output.
• Report which rows need manual investigation.

TODO

• Script to add WOJ columns
• Script to add POW columns
• Script to add SYMPOD columns
• Script to report problematic rows

I hope that this can be seen as helpful in the long run. I'm open to suggestions. This relates to #2