Fix keyword spotting. (#1689)

Reset the stream right after detecting a keyword

flutter/sherpa_onnx/lib/src/keyword_spotter.dart

@@ -168,6 +168,10 @@ class KeywordSpotter {
     SherpaOnnxBindings.decodeKeywordStream?.call(ptr, stream.ptr);
   }
 
+  void reset(OnlineStream stream) {
+    SherpaOnnxBindings.resetKeywordStream?.call(ptr, stream.ptr);
+  }
+
   Pointer<SherpaOnnxKeywordSpotter> ptr;
   KeywordSpotterConfig config;
 }

flutter/sherpa_onnx/lib/src/sherpa_onnx_bindings.dart

@@ -667,6 +667,12 @@ typedef DecodeKeywordStreamNative = Void Function(
 typedef DecodeKeywordStream = void Function(
     Pointer<SherpaOnnxKeywordSpotter>, Pointer<SherpaOnnxOnlineStream>);
 
+typedef ResetKeywordStreamNative = Void Function(
+    Pointer<SherpaOnnxKeywordSpotter>, Pointer<SherpaOnnxOnlineStream>);
+
+typedef ResetKeywordStream = void Function(
+    Pointer<SherpaOnnxKeywordSpotter>, Pointer<SherpaOnnxOnlineStream>);
+
 typedef GetKeywordResultAsJsonNative = Pointer<Utf8> Function(
     Pointer<SherpaOnnxKeywordSpotter>, Pointer<SherpaOnnxOnlineStream>);
 
@@ -1157,6 +1163,7 @@ class SherpaOnnxBindings {
   static CreateKeywordStreamWithKeywords? createKeywordStreamWithKeywords;
   static IsKeywordStreamReady? isKeywordStreamReady;
   static DecodeKeywordStream? decodeKeywordStream;
+  static ResetKeywordStream? resetKeywordStream;
   static GetKeywordResultAsJson? getKeywordResultAsJson;
   static FreeKeywordResultJson? freeKeywordResultJson;
 
@@ -1459,6 +1466,11 @@ class SherpaOnnxBindings {
             'SherpaOnnxDecodeKeywordStream')
         .asFunction();
 
+    resetKeywordStream ??= dynamicLibrary
+        .lookup<NativeFunction<ResetKeywordStreamNative>>(
+            'SherpaOnnxResetKeywordStream')
+        .asFunction();
+
     getKeywordResultAsJson ??= dynamicLibrary
         .lookup<NativeFunction<GetKeywordResultAsJsonNative>>(
             'SherpaOnnxGetKeywordResultAsJson')