[maru_sqlite] Build Proper Paging

The Maru-based project is using a simplistic paging mechanism right now. Look at how to make it more intuitive, perhaps by using a more HATEOAS approach to direct the flow.

Also look at [Scrivener.Ecto](https://github.com/drewolson/scrivener_ecto) ([ElixirCasts.io](https://elixircasts.io/elixir-pagination-with-scrivener) tutorial).