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/python/python3/CMakeLists.txt

@@ -0,0 +1,37 @@
+if(NOT PYTHON3_INCLUDE_PATH OR NOT PYTHON3_NUMPY_INCLUDE_DIRS)
+  ocv_module_disable(python3)
+endif()
+
+# Problem in numpy >=1.15 <1.17
+if(PYTHON3_LIMITED_API
+    AND NOT PYTHON3_NUMPY_VERSION VERSION_LESS "1.15"
+    AND PYTHON3_NUMPY_VERSION VERSION_LESS "1.17"
+  )
+  message(WARNING "Current NUMPY version (${PYTHON3_NUMPY_VERSION}) is not compatible with LIMITED_API.")
+  set(PYTHON3_LIMITED_API OFF)
+endif()
+
+set(the_description "The python3 bindings")
+set(MODULE_NAME python3)
+set(MODULE_INSTALL_SUBDIR python3)
+
+set(_ocv_extra_modules_path ${CMAKE_CURRENT_LIST_DIR}/../package/extra_modules)
+set(_old_ocv_python_extra_modules_path ${OCV_PYTHON_EXTRA_MODULES_PATH})
+
+if("${OCV_PYTHON_EXTRA_MODULES_PATH}" STREQUAL "")
+  set(OCV_PYTHON_EXTRA_MODULES_PATH ${_ocv_extra_modules_path})
+else()
+  list(APPEND OCV_PYTHON_EXTRA_MODULES_PATH ${_ocv_extra_modules_path})
+endif()
+
+unset(_ocv_extra_modules_path)
+
+set(PYTHON PYTHON3)
+
+include(../common.cmake)
+
+set(OCV_PYTHON_EXTRA_MODULES_PATH ${_old_ocv_python_extra_modules_path})
+
+unset(_old_ocv_python_extra_modules_path)
+unset(MODULE_NAME)
+unset(MODULE_INSTALL_SUBDIR)