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/test/infer/gapi_infer_tests.cpp

@@ -0,0 +1,79 @@
+// This file is part of OpenCV project.
+// It is subject to the license terms in the LICENSE file found in the top-level directory
+// of this distribution and at http://opencv.org/license.html.
+//
+// Copyright (C) 2020 Intel Corporation
+
+#include "../test_precomp.hpp"
+
+// These tests verify some parts of cv::gapi::infer<> API
+// regardless of the backend used
+
+namespace opencv_test {
+namespace {
+template<class A, class B> using Check = cv::detail::valid_infer2_types<A, B>;
+
+TEST(Infer, ValidInfer2Types)
+{
+    // Compiled == passed!
+
+    // Argument block 1
+    static_assert(Check< std::tuple<cv::GMat>   // Net
+                       , std::tuple<cv::GMat> > // Call
+                  ::value == true, "Must work");
+
+    static_assert(Check< std::tuple<cv::GMat, cv::GMat>   // Net
+                       , std::tuple<cv::GMat, cv::GMat> > // Call
+                  ::value == true, "Must work");
+
+    // Argument block 2
+    static_assert(Check< std::tuple<cv::GMat>             // Net
+                       , std::tuple<cv::Rect> >           // Call
+                  ::value == true, "Must work");
+
+    static_assert(Check< std::tuple<cv::GMat, cv::GMat>   // Net
+                       , std::tuple<cv::Rect, cv::Rect> > // Call
+                  ::value == true, "Must work");
+
+    // Argument block 3 (mixed cases)
+    static_assert(Check< std::tuple<cv::GMat, cv::GMat>   // Net
+                       , std::tuple<cv::GMat, cv::Rect> > // Call
+                  ::value == true, "Must work");
+
+    static_assert(Check< std::tuple<cv::GMat, cv::GMat>   // Net
+                       , std::tuple<cv::Rect, cv::GMat> > // Call
+                  ::value == true, "Must work");
+
+    // Argument block 4 (super-mixed)
+    static_assert(Check< std::tuple<cv::GMat, cv::GMat, cv::GMat>   // Net
+                       , std::tuple<cv::Rect, cv::GMat, cv::Rect> > // Call
+                  ::value == true, "Must work");
+
+    // Argument block 5 (mainly negative)
+    static_assert(Check< std::tuple<cv::GMat>             // Net
+                       , std::tuple<int> >                // Call
+                  ::value == false, "This type(s) shouldn't pass");
+
+    static_assert(Check< std::tuple<cv::GMat, cv::GMat>   // Net
+                       , std::tuple<int, cv::Rect> >      // Call
+                  ::value == false, "This type(s) shouldn't pass");
+
+    static_assert(Check< std::tuple<cv::GMat, cv::GMat>   // Net
+                       , std::tuple<cv::Rect, cv::Point> >// Call
+                  ::value == false, "This type(s) shouldn't pass");
+
+    // Argument block 5 (wrong args length)
+    static_assert(Check< std::tuple<cv::GMat, cv::GMat>   // Net
+                       , std::tuple<cv::GMat> >           // Call
+                  ::value == false, "Should fail -- not enough args");
+
+    static_assert(Check< std::tuple<cv::GMat, cv::GMat>   // Net
+                       , std::tuple<cv::Rect> >           // Call
+                  ::value == false, "Should fail -- not enough args");
+
+    static_assert(Check< std::tuple<cv::GMat, cv::GMat>             // Net
+                       , std::tuple<cv::Rect, cv::Rect, cv::GMat> > // Call
+                  ::value == false, "Should fail -- too much args");
+}
+} // anonymous namespace
+} // namespace opencv_test