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/modules/gapi/samples/slides_blur_gapi.cpp

@@ -0,0 +1,19 @@
+#include <opencv2/gapi.hpp>                            // G-API framework header
+#include <opencv2/gapi/imgproc.hpp>                    // cv::gapi::blur()
+#include <opencv2/highgui.hpp>                         // cv::imread/imwrite
+
+int main(int argc, char *argv[]) {
+    if (argc < 3) return 1;
+
+    cv::GMat in;                                       // Express the graph:
+    cv::GMat out = cv::gapi::blur(in, cv::Size(3,3));  // `out` is a result of `blur` of `in`
+
+    cv::Mat in_mat = cv::imread(argv[1]);              // Get the real data
+    cv::Mat out_mat;                                   // Output buffer (may be empty)
+
+    cv::GComputation(cv::GIn(in), cv::GOut(out))       // Declare a graph from `in` to `out`
+        .apply(cv::gin(in_mat), cv::gout(out_mat));    // ...and run it immediately
+
+    cv::imwrite(argv[2], out_mat);                     // Save the result
+    return 0;
+}