pkgdb-web: Catalog generation data as dicts

It turns out that returning lists of different values make it annoying to
deserialize in typed languages. Here's an endpoint returning the same data as
a list of dicts.

git-svn-id: svn+ssh://svn.code.sf.net/p/gar/code/csw/mgar/gar/v2@23210 d3b55034-1cff-0310-a425-aefe953e1e90