Support Dynamic Binding scenarios (non .NET languages)

At first I understood that we could pass somme parameters to the bindings `out` in `function.json` (`{name}` is used in your samples) by adding them in the object passed to the `done` function but it seems that these parameters are taken from the original input message. Do you think it would be possible to use the object passed to `done` as parameters for output binding? (could be used to define the blob name, the content, etc)