DwC-A should not have data files without meta.xml entries

[kueda]

Per globalbioticinteractions/globalbioticinteractions#427 (comment), when we use the make_api_all_taxon_data method, we just write a taxa.csv file into the archive without describing what it is and what its fields are in meta.xml. Instead, I think we should treat it like an extension to the observation core so it gets described in meta.xml.

There's also a lot of refactoring we could do in archive.rb, e.g. make_descriptor and make_descriptor both seem to contain a lot of logic that could be moved into the extension classes, but maybe that's out of scope.

[pleary]

I just focused on the ticket title and not the refactoring. I removed the make_api_all_taxon_data method and associated archive option since we aren't using it anymore. I'm not aware of other files that will get created that aren't documented in meta.xml