[API] Add access to individual survey results data via entities API

[SachaG]

Current sample request:

{
  entities(ids: "aspect_ratio") {
    id
    appearsIn {
      as
      question {
        id
      }
      edition {
        id
      }
      section {
        id
      }
      survey {
        id
      }
    }
  }
}

• Add a way to get specific data