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-mobile/highgui/include/opencv2/highgui.hpp

@@ -0,0 +1,17 @@
+//
+// Copyright (C) 2021 nihui
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//         http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+#include "opencv2/highgui/highgui.hpp"

3rdparty/opencv-mobile/highgui/include/opencv2/highgui/highgui.hpp

@@ -0,0 +1,62 @@
+//
+// Copyright (C) 2021 nihui
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//         http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+#ifndef OPENCV_HIGHGUI_HPP
+#define OPENCV_HIGHGUI_HPP
+
+#include "opencv2/core.hpp"
+
+enum
+{
+    CV_LOAD_IMAGE_UNCHANGED     = -1,
+    CV_LOAD_IMAGE_GRAYSCALE     = 0,
+    CV_LOAD_IMAGE_COLOR         = 1,
+};
+
+enum
+{
+    CV_IMWRITE_JPEG_QUALITY     = 1
+};
+
+namespace cv {
+
+enum ImreadModes
+{
+    IMREAD_UNCHANGED            = -1,
+    IMREAD_GRAYSCALE            = 0,
+    IMREAD_COLOR                = 1
+};
+
+enum ImwriteFlags
+{
+    IMWRITE_JPEG_QUALITY        = 1
+};
+
+CV_EXPORTS_W Mat imread(const String& filename, int flags = IMREAD_COLOR);
+
+CV_EXPORTS_W bool imwrite(const String& filename, InputArray img, const std::vector<int>& params = std::vector<int>());
+
+CV_EXPORTS_W Mat imdecode(InputArray buf, int flags);
+
+CV_EXPORTS_W bool imencode(const String& ext, InputArray img, CV_OUT std::vector<uchar>& buf, const std::vector<int>& params = std::vector<int>());
+
+CV_EXPORTS_W void imshow(const String& winname, InputArray mat);
+
+CV_EXPORTS_W int waitKey(int delay = 0);
+
+} // namespace cv
+
+#endif // OPENCV_HIGHGUI_HPP