function aliasField(field, aliasPrefix) {
  const aliasNode = field.alias ? field.alias : field.name
  return {
    ...field,
    alias: {
      ...aliasNode,
      value: aliasPrefix + aliasNode.value,
    },
  }
}
Returns a new FieldNode with prefixed alias

Example. Given prefix === "gatsby1_" transforms:
  { foo } -> { gatsby1_foo: foo }
  { foo: bar } -> { gatsby1_foo: bar }