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/samples/android/tutorial-4-opencl/CMakeLists.txt

@@ -0,0 +1,27 @@
+set(sample example-tutorial-4-opencl)
+if(NOT DEFINED ANDROID_OPENCL_SDK)
+  message(STATUS "Sample ${sample} is disabled, because ANDROID_OPENCL_SDK is not specified")
+  return()
+endif()
+if(ANDROID_NATIVE_API_LEVEL LESS 14)
+  message(STATUS "Sample ${sample} is disabled, because ANDROID_NATIVE_API_LEVEL < 14")
+  return()
+endif()
+
+if(BUILD_FAT_JAVA_LIB)
+  set(native_deps opencv_java)
+else()
+  set(native_deps opencv_imgproc)
+endif()
+
+include_directories(${ANDROID_OPENCL_SDK}/include)
+link_directories(${ANDROID_OPENCL_SDK}/lib/${ANDROID_NDK_ABI_NAME})
+add_android_project(${sample} "${CMAKE_CURRENT_SOURCE_DIR}"
+    LIBRARY_DEPS "${OPENCV_ANDROID_LIB_DIR}"
+    SDK_TARGET 21 "${ANDROID_SDK_TARGET}"
+    NATIVE_DEPS ${native_deps} -lGLESv2 -lEGL -lOpenCL
+    COPY_LIBS YES
+)
+if(TARGET ${sample})
+  add_dependencies(opencv_android_examples ${sample})
+endif()