Attempt to auto-discover shapefile when nested within folder(s) in zip file

[brendan-ward]

If a shapefile is nested in a subfolder within a zip file (example here), GDAL will emit a misleading error about the zip file not being a recognized format.

For example, if you have <zip file>/layers/POLYGON.shp, calling any of the read functions on <zip file> as the path will fail, whereas if you pass in the path to the shapefile within the zip file, it works fine This is confusing to users and inconvenient, given that other tools like QGIS will open it fine.

We can't do this for remotely hosted files, but it seems theoretically possible to do so with local or in-memory files.