Support pagination

[briantist]

We currently don't support pagination at all, which isn't too much of a problem for content that's already local to artifactory unless you have a huge number of collections, because it will return all the results, but it is a problem for upstream proxying support since we only ever get the first set of results from an upstream. The query string parameters are passed through, so for example if page_size=100 is passed to the original request, we do pass that along, but in older galaxy clients they don't, and the upstream server's default page size is 10. Any results that aren't in the first result, whatever size that is, will not be returned.

I guess realistically, it hasn't come up much since in most cases clients are looking for either the latest version, or a specific version, or a range that probably falls within the first set of results.

But this is a quite a deficiency.