[Feature]: durable function handlers indirectly inherited from DurableHandler

[zhongkechen]

What would you like?

I would like to create durable function handlers that are indirectly inherited from DurableHandler, e.g.

public abstract class AbstractDurableHandler<TRequest, TResponse> extends DurableHandler<DurableEnvelope, TResponse> {

  @Override
  public final TResponse handleRequest(final DurableEnvelope envelope, final DurableContext context) {
    //...
  }
}

public class InvoicesDurableHandler extends AbstractDurableHandler<GetInvoicesRequest, GetInvoicesResponse> {
    //...
}

Possible Implementation

No response

Is this a breaking change?

No

Does this require an RFC?

No

Additional Context

No response