Add option to strip out all but core set of name translations

[nvkelso]

We have ~21 core Tilezen languages but there are many more than that in OSM.

There's also a subset of "UN" languages to think about:

• name:en // English
• name:es // Spanish
• name:fr // French
• name:de // German
• name:ru // Russian
• name:zh // Chinese
• name:ar // Arabic
• name:pt // Portuguese

Add option to strip out all but core set of name translations