Update client to utilize pagination

Copied from https://github.com/cmu-delphi/covidcast-indicators/issues/197
Blocked by https://github.com/cmu-delphi/delphi-epidata/pull/184



┆Issue is synchronized with this [Asana task](https://app.asana.com/0/1198968030437421/1198970328404904) by [Unito](https://www.unito.io/learn-more)
