Nested published content data (issue#2)

[JackPenney]

Nesting the base fields on IPublishedContent under _contentData to prevent it clashing with user created doctype aliases

This would change the current format from

{
  content(id:1123) {
    ...on Blogpost {
      pageTitle
      excerpt
      categories
      id
      createDate
      creatorName
      name
    }
  }
}

to

{
  content(id:1123) {
    ...on Blogpost {
      pageTitle
      excerpt
      categories
      _contentData {
        id
        createDate
    creatorName
        name
        }
    }
  }
}