Create filter class that can be passed as parameter on all requests

Need to figure out if this lives at client level or api level. ~In meantime, limit parameter should be undeprecatedi~ `limit` parameter no longer exists.

This is related to #153, but #153 is about automatically creating filters while this one is about allowing users to manually create and apply filters.

At the moment I can't remember whether filters have use outside of `sync` or not. If they don't, someone let me know, and I'll modify title accordingly.

No file or test paths are named. Start by tracing how requests are handled at the client and API levels, then check whether filters are used outside sync; done means users can manually create and apply a filter to every request, distinct from the automatic filter creation in #153.

Written by the indexing model from the issue text.