[Feature] support multiple database sync for flink cdc sync action

### Search before asking

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

### Motivation

flink cdc support multiple database sync,I think we also support it.

for some databases with a large number but a small amount of data, we can use one job to complete data synchronization and reduce resources.

### Solution

_No response_

### Anything else?

_No response_

### Are you willing to submit a PR?

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

The issue concerns the Flink CDC sync action and proposes synchronizing multiple databases in one job. No files, tests, or implementation entry points are named, so first locate the existing Flink CDC sync action and determine its current database scope. Done should mean one job can synchronize multiple databases while reducing duplicated resource use.

Written by the indexing model from the issue text.