Move "fetch next page" into the views client

[kevinburke]

Right now each of the controllers fetches the next page into the cache. Maybe this should be the responsibility of the view client instead.

We'd have to deal with recursion in the view client - when fetching the next page, don't fetch the next next page.

[kevinburke]

(I'm thinking specifically for the phone number view, where we fetch 4 pages simultaneously)