Produces an entity but not an entire manifest

For now the produced data is a entity resulting of a single resqml/prodml/witsml entity translation. We should also provide a convert function that takes many resqml/prodml/witsml entities, and produce an entire manifest with each translated entities stored in the appropriate manifest key. We should obtain a file like this :

{
    "kind": "osdu:wks:Manifest:1.0.0",
    "ReferenceData": [
       ......
    ],
    "MasterData": [
       ......
    ],
    "Data": {
       ......
    }    
}

and not only the translation of one file that only produce element for the data key