[fn][Go] Go functions should support retry/dlq

### Search before asking

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

### Motivation

Go Functions do not support message retry or DLQ settings. Since the client has support for these and since they are already transported to the runtime, this should be a no-brainer.

### Solution

Use the transported DLQ/retry settings to bring the go functions in-line with the java ones

### Alternatives

The only alternative at this time is to detect retries automatically by inspecting messages manually and using the (not so great) `context.NewOutputMessage` API to manually to dispatch messages to the retry or DLQ topics.

### Anything else?

_No response_

### Are you willing to submit a PR?

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

Start by tracing how transported retry and DLQ settings reach Go Functions, then compare that behavior with the existing Java Functions implementation. Done means Go Functions use those settings for message retry and dead-letter routing without requiring manual message inspection or dispatch.

Written by the indexing model from the issue text.