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/include/opencv2/gapi/s11n/base.hpp

@@ -0,0 +1,80 @@
+// 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) 2020-2021 Intel Corporation
+
+#ifndef OPENCV_GAPI_S11N_BASE_HPP
+#define OPENCV_GAPI_S11N_BASE_HPP
+
+#include <opencv2/gapi/own/assert.hpp>
+#include <opencv2/gapi/own/exports.hpp>
+
+namespace cv {
+namespace gapi {
+
+/**
+ * @brief This namespace contains G-API serialization and
+ * deserialization functions and data structures.
+ */
+namespace s11n {
+struct IOStream;
+struct IIStream;
+
+namespace detail {
+
+//! @addtogroup gapi_serialization
+//! @{
+
+struct NotImplemented {
+};
+
+/** @brief This structure allows to implement serialization routines for custom types.
+ *
+ * The default S11N for custom types is not implemented.
+ *
+ * @note When providing an overloaded implementation for S11N with your type
+ * don't inherit it from NotImplemented structure.
+ *
+ * @note There are lots of overloaded >> and << operators for basic and OpenCV/G-API types
+ * which can be utilized when serializing a custom type.
+ *
+ * Example of usage:
+ * @snippet modules/gapi/samples/api_ref_snippets.cpp S11N usage
+ *
+ */
+template<typename T>
+struct S11N: public NotImplemented {
+    /**
+     * @brief This function allows user to serialize their custom type.
+     *
+     * @note The default overload throws an exception if called. User need to
+     * properly overload the function to use it.
+     */
+    static void serialize(IOStream &, const T &) {
+        GAPI_Assert(false && "No serialization routine is provided!");
+    }
+    /**
+     * @brief This function allows user to deserialize their custom type.
+     *
+     * @note The default overload throws an exception if called. User need to
+     * properly overload the function to use it.
+     */
+    static T deserialize(IIStream &) {
+        GAPI_Assert(false && "No deserialization routine is provided!");
+    }
+};
+
+/// @private -- Exclude this struct from OpenCV documentation
+template<typename T> struct has_S11N_spec {
+    static constexpr bool value = !std::is_base_of<NotImplemented,
+                                        S11N<typename std::decay<T>::type>>::value;
+};
+//! @} gapi_serialization
+
+} // namespace detail
+} // namespace s11n
+} // namespace gapi
+} // namespace cv
+
+#endif // OPENCV_GAPI_S11N_BASE_HPP