Add a system to make creating a delegate-style class easier.

[cputnam-a11y]

When extending certain classes, it can be helpful to delegate parts of implementation to another instance of said class. Given a class as follows

static class ClassyGreedyAnteater {
  void doVeryImportantLogicThatIsRequiredToBeDoneCorrectlyToPreventCrashes() {
    // very important logic that is specific to this instance :)
  }
}

If I want to extend this class, but I still need the very important logic to take place, then I must follow a pattern like so:

@Extend(
  targetClass = "ClassyGreedyAnteater",
  unsafe = false
)
public interface AcidicCleverCamel {
  @Field("delegate")
  @Field.Final
  Object delegate();

  @Overrides("doVeryImportantLogicThatIsRequiredToBeDoneCorrectlyToPreventCrashes")
  void  doVeryImportantLogicThatIsRequiredToBeDoneCorrectlyToPreventCrashesImpl() {
    callDoVeryImportantLogicThatIsRequiredToBeDoneCorrectlyToPreventCrashes(delegate());
  }

  @Open(
    targetName = "ClassyGreedyAnteater",
    name = "doVeryImportantLogicThatIsRequiredToBeDoneCorrectlyToPreventCrashes",
    type = Open.Type.VIRTUAL
  )
  private static callDoVeryImportantLogicThatIsRequiredToBeDoneCorrectlyToPreventCrashes(
    @Coerce(targetName = "ClassyGreedyAnteater") Object instance
  ) {
    throw new AssertionError("Failed to transform class and replace @Open method");
  }
}

it would be nice to have an easier way to implement this delegate pattern