[Bug] Chain Table read failure

### Search before asking

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

### Paimon-cpp version

latest

### Minimal reproduce step

Read a Chain Table with paimon-cpp

### What doesn't meet your expectations?

It throws runtime error:
`invalid data split byte stream, remaining {} bytes after deserializing`

### Anything else?

https://paimon.apache.org/docs/master/primary-key-table/chain-table/

### Are you willing to submit a PR?

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

Start with the Chain Table documentation at https://paimon.apache.org/docs/master/primary-key-table/chain-table/ and reproduce the failure by reading a Chain Table with paimon-cpp. Trace the data-split deserialization path that produces “invalid data split byte stream, remaining {} bytes after deserializing”; done means Chain Table reads no longer raise this runtime error.

Written by the indexing model from the issue text.