[Feature Request] There is no Transaction Support in C++ client API

### Search before asking

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

### Version

We are actively using Apache pulsar in our C/C++ product, however we came across to an issue that there is no Transaction Client API's were support available. Could you please let us know, when this feature will be included in Pulsar Client API ? kindly include this as earl as it is very much needed for our product !!

Thanks alot!

### Minimal reproduce step

No Transaction support in C++ Client API

### What did you expect to see?

Pulsar must also support transaction in C++ client

### What did you see instead?

No Transaction Support in C++ client

### Anything else?

kindly Make this transaction support inorder to use Pulsar actively across all existing C++ products

### Are you willing to submit a PR?

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

この issue は C++ クライアント API でのトランザクションサポートを求めていますが、ファイル、テスト、エントリーポイントについては何も示していません。まず、既存の C++ クライアント API と、プロジェクト内の他の場所にあるトランザクションサポートを特定してください。完了とするには、定義済みのトランザクション設計、実装範囲、および対応するテストが必要です。

索引モデルが issue の本文から書いたものです。