Simplify multi-language label

[morpheus-87]

Now:

"label": {
      "translations": [
        {
          "locale": "de_DE",
          "text": "Deutscher Titel"
        },
        {
          "locale": "en",
          "text": "Englischer Titel"
        }
      ]
    }

Should be:

"label": {
      "de_DE": "Deutscher Titel"
      "en": "Englischer Titel"
    }

[morpheus-87]

Is done with #64.