[Feature] CDC Ingestion should support -U and +U messages

### Search before asking

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

### Motivation

I want that reading -U and +U messages from audit log table of paimon table with input changelog producer, but paimon CDC parser does not produce -U and +U messages.

### Solution

I suggest paimon CDC parser produce -U and +U messages for the downstream tasks.

### Anything else?

_No response_

### Are you willing to submit a PR?

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

Start by locating the Paimon CDC parser and the audit log table handling described in the issue, then trace how changelog messages reach downstream tasks. Confirm the current behavior for -U and +U messages and define completion as producing both message types for CDC input without breaking existing changelog handling.

Written by the indexing model from the issue text.