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/flann/misc/python/pyopencv_flann.hpp

@@ -0,0 +1,87 @@
+#ifdef HAVE_OPENCV_FLANN
+typedef cvflann::flann_distance_t cvflann_flann_distance_t;
+typedef cvflann::flann_algorithm_t cvflann_flann_algorithm_t;
+
+template<>
+PyObject* pyopencv_from(const cvflann_flann_algorithm_t& value)
+{
+    return PyInt_FromLong(int(value));
+}
+
+template<>
+PyObject* pyopencv_from(const cvflann_flann_distance_t& value)
+{
+    return PyInt_FromLong(int(value));
+}
+
+template<>
+bool pyopencv_to(PyObject *o, cv::flann::IndexParams& p, const ArgInfo& info)
+{
+    CV_UNUSED(info);
+    bool ok = true;
+    PyObject* key = NULL;
+    PyObject* item = NULL;
+    Py_ssize_t pos = 0;
+
+    if (!o || o == Py_None)
+        return true;
+
+    if(PyDict_Check(o)) {
+        while(PyDict_Next(o, &pos, &key, &item))
+        {
+            // get key
+            std::string k;
+            if (!getUnicodeString(key, k))
+            {
+                ok = false;
+                break;
+            }
+            // get value
+            if( !!PyBool_Check(item) )
+            {
+                p.setBool(k, item == Py_True);
+            }
+            else if( PyInt_Check(item) )
+            {
+                int value = (int)PyInt_AsLong(item);
+                if( strcmp(k.c_str(), "algorithm") == 0 )
+                    p.setAlgorithm(value);
+                else
+                    p.setInt(k, value);
+            }
+            else if( PyFloat_Check(item) )
+            {
+                double value = PyFloat_AsDouble(item);
+                p.setDouble(k, value);
+            }
+            else
+            {
+                std::string val_str;
+                if (!getUnicodeString(item, val_str))
+                {
+                    ok = false;
+                    break;
+                }
+                p.setString(k, val_str);
+            }
+        }
+    }
+
+    return ok && !PyErr_Occurred();
+}
+
+template<>
+bool pyopencv_to(PyObject* obj, cv::flann::SearchParams & value, const ArgInfo& info)
+{
+    return pyopencv_to<cv::flann::IndexParams>(obj, value, info);
+}
+
+template<>
+bool pyopencv_to(PyObject *o, cvflann::flann_distance_t& dist, const ArgInfo& info)
+{
+    int d = (int)dist;
+    bool ok = pyopencv_to(o, d, info);
+    dist = (cvflann::flann_distance_t)d;
+    return ok;
+}
+#endif