[Feature] Add a listener mechanism for Paimon

### Search before asking

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

### Motivation

In the process of integrating services like the Amoro Lakehouse management system with Paimon, it is necessary to timely perceive the state changes of Paimon's tables, such as whether there is data commit, the current compaction status of the write task, and so on. Therefore, a Listener mechanism is introduced to synchronize the state to the outside world.

### Solution

_No response_

### Anything else?

_No response_

### Are you willing to submit a PR?

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

No files, tests, or entry points are named, and the proposed solution is empty. Start by mapping where table data commits and write-task compaction state are represented, then clarify the listener API and lifecycle with maintainers. Done means external services can reliably receive the required table-state changes.

Written by the indexing model from the issue text.