Resolve input types with preResolveTypes same as selection sets

[standy]

Option preResolveTypes should work with input types in the same way as with output types

For example (https://github.com/dotansimha/graphql-code-generator/blob/master/dev-test/star-wars/types.preResolveTypes.ts#L237)

export type CreateReviewForEpisodeMutationVariables = {
   /* ... */
  review: ReviewInput;
};

should be

export type CreateReviewForEpisodeMutationVariables = {
  /* ... */
  review: {
    /** 0-5 stars */
    stars: number;
    /** Comment about the movie, optional */
    commentary?: string;
    /** Favorite color, optional */
    favoriteColor?: Maybe<{
      red: number;
      green: number;
      blue: number;
    }>;
  }
};