Add PlaceService implementation

Yo dudes, just as we talked about:

[PlaceService](https://github.com/Vizzuality/gfw/blob/feature/refactor-june-placeservice/app/assets/javascripts/map/services/PlaceService.js)
[PlaceService_spec](https://github.com/Vizzuality/gfw/blob/feature/refactor-june-placeservice/jstest/spec/PlaceService_spec.js)

It handles our two use cases:

1. A route change needs to update view state across the application
1. A view change needs to update the route based on view state across the application

Read the [docs here](https://github.com/Vizzuality/gfw/blob/feature/refactor-june-placeservice/app/assets/javascripts/map/services/PlaceService.js#L2-L43) for a bit more detail on how this things works with events. 

Let's hop on HC to talk it through!!  :D