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/videoio/test/test_main.cpp

@@ -0,0 +1,25 @@
+// 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.
+#include "test_precomp.hpp"
+#include <opencv2/core/utils/logger.hpp>
+
+#if defined(HAVE_HPX)
+    #include <hpx/hpx_main.hpp>
+#endif
+
+static
+void initTests()
+{
+#ifndef WINRT  // missing getenv
+    const std::vector<cv::VideoCaptureAPIs> backends = cv::videoio_registry::getStreamBackends();
+    const char* requireFFmpeg = getenv("OPENCV_TEST_VIDEOIO_BACKEND_REQUIRE_FFMPEG");
+    if (requireFFmpeg && !isBackendAvailable(cv::CAP_FFMPEG, backends))
+    {
+        CV_LOG_FATAL(NULL, "OpenCV-Test: required FFmpeg backend is not available (broken plugin?). STOP.");
+        exit(1);
+    }
+#endif
+}
+
+CV_TEST_MAIN("highgui", initTests())