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/misc/python/shadow_gapi.hpp

@@ -0,0 +1,83 @@
+#error This is a shadow header file, which is not intended for processing by any compiler. \
+       Only bindings parser should handle this file.
+
+namespace cv
+{
+struct GAPI_EXPORTS_W_SIMPLE GCompileArg
+{
+    GAPI_WRAP GCompileArg(gapi::GKernelPackage arg);
+    GAPI_WRAP GCompileArg(gapi::GNetPackage arg);
+    GAPI_WRAP GCompileArg(gapi::streaming::queue_capacity arg);
+};
+
+class GAPI_EXPORTS_W_SIMPLE GInferInputs
+{
+public:
+    GAPI_WRAP GInferInputs();
+    GAPI_WRAP GInferInputs& setInput(const std::string& name, const cv::GMat&   value);
+    GAPI_WRAP GInferInputs& setInput(const std::string& name, const cv::GFrame& value);
+};
+
+class GAPI_EXPORTS_W_SIMPLE GInferListInputs
+{
+public:
+    GAPI_WRAP GInferListInputs();
+    GAPI_WRAP GInferListInputs setInput(const std::string& name, const cv::GArray<cv::GMat>& value);
+    GAPI_WRAP GInferListInputs setInput(const std::string& name, const cv::GArray<cv::Rect>& value);
+};
+
+class GAPI_EXPORTS_W_SIMPLE GInferOutputs
+{
+public:
+    GAPI_WRAP GInferOutputs();
+    GAPI_WRAP cv::GMat at(const std::string& name);
+};
+
+class GAPI_EXPORTS_W_SIMPLE GInferListOutputs
+{
+public:
+    GAPI_WRAP GInferListOutputs();
+    GAPI_WRAP cv::GArray<cv::GMat> at(const std::string& name);
+};
+
+namespace gapi
+{
+namespace wip
+{
+class GAPI_EXPORTS_W IStreamSource { };
+namespace draw
+{
+    // NB: These render primitives are partially wrapped in shadow file
+    // because cv::Rect conflicts with cv::gapi::wip::draw::Rect in python generator
+    // and cv::Rect2i breaks standalone mode.
+    struct Rect
+    {
+        GAPI_WRAP Rect(const cv::Rect2i& rect_,
+                       const cv::Scalar& color_,
+                       int thick_ = 1,
+                       int lt_ = 8,
+                       int shift_ = 0);
+    };
+
+    struct Mosaic
+    {
+        GAPI_WRAP Mosaic(const cv::Rect2i& mos_, int cellSz_, int decim_);
+    };
+} // namespace draw
+} // namespace wip
+namespace streaming
+{
+    // FIXME: Extend to work with an arbitrary G-type.
+    cv::GOpaque<int64_t> GAPI_EXPORTS_W timestamp(cv::GMat);
+    cv::GOpaque<int64_t> GAPI_EXPORTS_W seqNo(cv::GMat);
+    cv::GOpaque<int64_t> GAPI_EXPORTS_W seq_id(cv::GMat);
+
+    GAPI_EXPORTS_W cv::GMat desync(const cv::GMat &g);
+} // namespace streaming
+} // namespace gapi
+
+namespace detail
+{
+    gapi::GNetParam GAPI_EXPORTS_W strip(gapi::ie::PyParams params);
+} // namespace detail
+} // namespace cv