Better support for lazy fields

[bwaidelich]

Currently, the whole object of a query or mutation result is serialized at once and the only way to add lazy evaluated fields is to use custom resolvers.

It would be useful to be able to mark methods as part of the API, for example:

final class Api
{
    #[Query]
    public function someQuery(): SomeObject {
        return new SomeObject('testing');
    }
}

final class SomeObject {
    public function __construct(
        public readonly string $someString,
    ) {}

    #[Field]
    public function someLazyField(): string {
        return 'only evaluated if called';
    }
}

[bwaidelich]

Idea: Add "name" and "lazy" parameter:

final class SomeObject {

   protected string $foo;

    #[Field(name: 'foo')]
    public function getFoo(): string {
    }

   public jsonSerialize(): array {
     return ['foo' => $this->foo];
   }
}