MNT: Extract all NE resources from the zip file

[greglucas]

Rationale

The various Natural Earth datasets can have different file members within them. Rather than explicitly iterating through the list of expected files, lets just extract all of them. This adds a datasetname.README.txt and datasetname.VERSION.txt which could be helpful for debugging purposes too and the sizes are very small for the extra files.

closes #2319

Implications

[greglucas]

This is failing because we allow the renaming of file contents when extracting an archive. The content within the zipfile is: ne_110m_rivers_lake_centerlines.shp, but the download template wants to rename that to: {category}_{resolution}_{name}.shp. I'm not sure I fully agree with the ability to rename a file coming from an archive, versus making the reader handle different formatted filenames, but I do sort of see why you may want to do that to try and organize things your own way too.