Refactor paginator making it more pythonic

[piraz]

The paginator is one pretty old code I'm maintaining though those years in several languages and several frameworks, it was developed to provide help to create or handle a UI pagination and it's implementation in the server side.

As firenado API's can benefit from a better pagination management one of the objectives from the this effort would be to prepare our logic to provide better pagination management for schedulers, API Frontend/Backend, specialized servers and queued based components(i.e. producers, rpc clients, workers).