[c++] Add to_arrow_batch_reader support in C++ binding

### Search before asking

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

### Description

In #446 , it added `RecordBatchLogReader` in Rust core and exposed `to_arrow_batch_reader()` in the Python binding.

The C++ binding does not yet surface this functionality.

### Willingness to contribute

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