feat: 切换后端至PaddleOCR-NCNN，切换工程为CMake

1.项目后端整体迁移至PaddleOCR-NCNN算法，已通过基本的兼容性测试
2.工程改为使用CMake组织，后续为了更好地兼容第三方库，不再提供QMake工程
3.重整权利声明文件，重整代码工程，确保最小化侵权风险

Log: 切换后端至PaddleOCR-NCNN，切换工程为CMake
Change-Id: I4d5d2c5d37505a4a24b389b1a4c5d12f17bfa38c

3rdparty/opencv-4.5.4/samples/cpp/tutorial_code/ImgProc/Threshold.cpp

@@ -0,0 +1,87 @@
+/**
+ * @file Threshold.cpp
+ * @brief Sample code that shows how to use the diverse threshold options offered by OpenCV
+ * @author OpenCV team
+ */
+
+#include "opencv2/imgproc.hpp"
+#include "opencv2/imgcodecs.hpp"
+#include "opencv2/highgui.hpp"
+#include <iostream>
+
+using namespace cv;
+using std::cout;
+
+/// Global variables
+
+int threshold_value = 0;
+int threshold_type = 3;
+int const max_value = 255;
+int const max_type = 4;
+int const max_binary_value = 255;
+
+Mat src, src_gray, dst;
+const char* window_name = "Threshold Demo";
+
+const char* trackbar_type = "Type: \n 0: Binary \n 1: Binary Inverted \n 2: Truncate \n 3: To Zero \n 4: To Zero Inverted";
+const char* trackbar_value = "Value";
+
+//![Threshold_Demo]
+/**
+ * @function Threshold_Demo
+ */
+static void Threshold_Demo( int, void* )
+{
+    /* 0: Binary
+     1: Binary Inverted
+     2: Threshold Truncated
+     3: Threshold to Zero
+     4: Threshold to Zero Inverted
+    */
+    threshold( src_gray, dst, threshold_value, max_binary_value, threshold_type );
+    imshow( window_name, dst );
+}
+//![Threshold_Demo]
+
+/**
+ * @function main
+ */
+int main( int argc, char** argv )
+{
+    //! [load]
+    String imageName("stuff.jpg"); // by default
+    if (argc > 1)
+    {
+        imageName = argv[1];
+    }
+    src = imread( samples::findFile( imageName ), IMREAD_COLOR ); // Load an image
+
+    if (src.empty())
+    {
+        cout << "Cannot read the image: " << imageName << std::endl;
+        return -1;
+    }
+
+    cvtColor( src, src_gray, COLOR_BGR2GRAY ); // Convert the image to Gray
+    //! [load]
+
+    //! [window]
+    namedWindow( window_name, WINDOW_AUTOSIZE ); // Create a window to display results
+    //! [window]
+
+    //! [trackbar]
+    createTrackbar( trackbar_type,
+                    window_name, &threshold_type,
+                    max_type, Threshold_Demo ); // Create a Trackbar to choose type of Threshold
+
+    createTrackbar( trackbar_value,
+                    window_name, &threshold_value,
+                    max_value, Threshold_Demo ); // Create a Trackbar to choose Threshold value
+    //! [trackbar]
+
+    Threshold_Demo( 0, 0 ); // Call the function to initialize
+
+    /// Wait until the user finishes the program
+    waitKey();
+    return 0;
+}