Carry non-fragment fields into the result for a fragment

[kraney]

A query on an interface that specifies common fields outside the fragment and other fields inside the fragment will fail with an error on the common fields. E.g.

query Area {
  Area {
    name
    __typename
    includes{
      name
      ...on Partition {
        resident
      }
    }
  }
}

This results in an "unable to resolve field Partition.name" error, while this works.

query Area {
  Area {
    name
    __typename
    includes{
      ...on Partition {
        name
        resident
      }
    }
  }
}

This fix keeps the common-level fields when processing a fragment

[johnymontana]

Great, thanks @kraney!