Support resolving Entities sent it through @requires resolution to types

[sshevlyagin]

Currently, if you're using dgs-framework with federation and use the @requires directive you don't benefit from the generated types,

for example if your schema was

type Car @key(fields "id") @extends {
  id: ID @external
  make: String @external
  model: String @external
  reviews: [Review] @requires(fields: "make model")
}

you data fetcher would be

@DgsData(parentType = "Car", field = "reviews")
public List<Review> getReviews(DgsDataFetchingEnvironment dfe) {
  String make = (String)dfe.getVariables().get("representations").get(0).get("make");
  String model = (String)dfe.getVariables().get("representations").get(0).get("model");
  return reviewService.getReviewList(make, model);
}

Is it possible to convert the variables under representations to a known type similar to what Expedia does in Kotlin? https://github.com/ExpediaGroup/graphql-kotlin/blob/245b4579103e5a20ea9f4d770786aad8e9c92eb1/generator/graphql-kotlin-federation/src/main/kotlin/com/expediagroup/graphql/generator/federation/execution/EntityResolver.kt