Support streaming zipformer CTC (#496)

* 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

sherpa-onnx/csrc/online-wenet-ctc-model.h

@@ -35,6 +35,12 @@ class OnlineWenetCtcModel : public OnlineCtcModel {
   //  - offset
   std::vector<Ort::Value> GetInitStates() const override;
 
+  std::vector<Ort::Value> StackStates(
+      std::vector<std::vector<Ort::Value>> states) const override;
+
+  std::vector<std::vector<Ort::Value>> UnStackStates(
+      std::vector<Ort::Value> states) const override;
+
   /**
    *
    * @param x A 3-D tensor of shape (N, T, C). N has to be 1.
@@ -63,6 +69,8 @@ class OnlineWenetCtcModel : public OnlineCtcModel {
   // before we process the next chunk.
   int32_t ChunkShift() const override;
 
+  bool SupportBatchProcessing() const override { return false; }
+
  private:
   class Impl;
   std::unique_ptr<Impl> impl_;