[Feature Request]: Kafka Metadata support

### What would you like to happen?

Migration: https://issues.apache.org/jira/browse/HOP-3871

It should be possible to read and set message metadata within hop.

The most important thing is the possibility to set the timestamp of the message in the producer

### Issue Priority

Priority: 3

### Issue Component

Component: Transforms

Start by reviewing the linked migration HOP-3871 and the Kafka-related transforms in Apache Hop; the issue does not name specific files or tests. Done means establishing how message metadata can be read and set within Hop, with producer message timestamps as the stated priority, then identifying the relevant validation coverage.

Written by the indexing model from the issue text.