Chaneges to opi_rtsp test application

- refactoring
  - can use normal YOLOv8 files converted to ONNX format
  - does not work with azaion ONNX files!

tmp/opi_rtsp/src-opencv-onnx/aiengineinferenceopencvonnx.h

@@ -0,0 +1,19 @@
+#pragma once
+
+#include <QObject>
+#include "aiengineinference.h"
+#include "src-opencv-onnx/inference.h"
+
+class AiEngineInferenceOpencvOnnx : public AiEngineInference
+{
+    Q_OBJECT
+public:
+    explicit AiEngineInferenceOpencvOnnx(QString modelPath, QObject *parent = nullptr);
+
+public slots:
+    void performInferenceSlot(cv::Mat frame) override;
+
+private:
+    //InferenceEngine *mEngine;
+    Inference mInference;
+};