* Support streaming zipformer CTC
* test online zipformer2 CTC
* Update doc of sherpa-onnx.cc
* Add Python APIs for streaming zipformer2 ctc
* Add Python API examples for streaming zipformer2 ctc
* Swift API for streaming zipformer2 CTC
* NodeJS API for streaming zipformer2 CTC
* Kotlin API for streaming zipformer2 CTC
* Golang API for streaming zipformer2 CTC
* C# API for streaming zipformer2 CTC
* Release v1.9.6
* Refactor online recognizer.
Make it easier to support other streaming models.
Note that it is a breaking change for the Python API.
`sherpa_onnx.OnlineRecognizer()` used before should be
replaced by `sherpa_onnx.OnlineRecognizer.from_transducer()`.
