Remove total field in Pager, add count fn.

[n1k0]

This patch removes the total field of the Pager record type, because it's not available anymore for GET request in Kinto but only through an HEAD one. See related Kinto discussion here.

That's why the patch also adds a new count function so users can separately retrieve the total number of records available in a given collection.

This is gonna trigger a major release:

$ elm diff
This is a MAJOR change.

---- Kinto - MAJOR ----

    Added:
        count :
            Kinto.Resource a
            -> (Result.Result Kinto.Error Basics.Int -> msg)
            -> Kinto.Client
            -> Kinto.Request msg
    
    Changed:
      - type alias Pager a =
            { client : Client
            , objects : List a
            , decoder : Decoder (List a)
            , total : Int
            , nextPage : Maybe Url
            }
      + type alias Pager a =
            { client : Kinto.Client
            , objects : List.List a
            , decoder : Json.Decode.Decoder (List.List a)
            , nextPage : Maybe.Maybe Kinto.Url
            }

[n1k0]

I need to update the examples.

[Natim]

Top merci!

[magopian]

Flawless 👍