[Feature] Support auto resolve memory reference for passing data across actions.

### Search before asking

- [x] I searched in the [issues](https://github.com/apache/flink-agents/issues) and found nothing similar.

### Description

`MemoryRef` is useful for passing large data across actions, which can reduce the event payload size and avoid unnecessary data SerDe.

Currently, user should manually resolve the memory reference to get the pointed data, like `event.ref.resolve(ctx)`, which is a little bit inconvenient. We should support hidden the resolve process in framework.

### Are you willing to submit a PR?

- [ ] I'm willing to submit a PR!