Recognizer deleteion safety + data control, remove repeating UTF8ToString() call from event system.

src/CommonModel.h

@@ -9,6 +9,7 @@ struct CommonModel {
   std::string storepath;
   std::string id;
   std::variant<VoskModel*, VoskSpkModel*> mdl;
+  
   void extractAndLoad(unsigned char* tarStart, int tarSize);
   int findWord(std::string word);
   CommonModel(int index, bool normalMdl, std::string storepath, std::string id, int tarStart, int tarSize);