Support zipped shapefiles within source zip

[stefanb]

Shapefiles are commonly zipped and many tools can open such shapefile as zip directly.
Sources may add some additional data (explanations, license, lookup tables....) next to such shapefile zip and then realease it all as a zip.

Related isues / PRs:

• Update city_of_banff.json openaddresses#5366 (comment)
• Slovenia: Get addresses from the new JGP portal in CSV form openaddresses#6102 (will be needed for buildings)
• ... possibly others...

[ingalls]

Oh boy, this makes my head hurt. Why do people do these things.

I'm going to move this to this repo: https://github.com/openaddresses/batch-machine