Allow modify model config at decode time for ASR (#1124)

sherpa-onnx/csrc/offline-recognizer.h

@@ -119,6 +119,15 @@ class OfflineRecognizer {
    */
   void DecodeStreams(OfflineStream **ss, int32_t n) const;
 
+  /** Onnxruntime Session objects are not affected by this method.
+  * The exact behavior can be defined by a specific recognizer impl.
+  * For instance, for the whisper recognizer, you can retrieve the language and task from
+  * the config and ignore any remaining fields in `config`.
+  */
+  void SetConfig(const OfflineRecognizerConfig &config);
+
+  OfflineRecognizerConfig GetConfig() const;
+
  private:
   std::unique_ptr<OfflineRecognizerImpl> impl_;
 };