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/test/test.py

@@ -0,0 +1,60 @@
+#!/usr/bin/env python
+'''
+Location of tests:
+- <opencv_src>/modules/python/test
+- <opencv_src>/modules/<module>/misc/python/test/
+'''
+
+from __future__ import print_function
+
+import sys
+sys.dont_write_bytecode = True  # Don't generate .pyc files / __pycache__ directories
+
+import os
+import unittest
+
+# Python 3 moved urlopen to urllib.requests
+try:
+    from urllib.request import urlopen
+except ImportError:
+    from urllib import urlopen
+
+from tests_common import NewOpenCVTests
+
+
+basedir = os.path.abspath(os.path.dirname(__file__))
+
+def load_tests(loader, tests, pattern):
+    cwd = os.getcwd()
+    config_file = 'opencv_python_tests.cfg'
+    locations = [cwd, basedir]
+    if os.path.exists(config_file):
+        with open(config_file, 'r') as f:
+            locations += [str(s).strip() for s in f.readlines()]
+    else:
+        print('WARNING: OpenCV tests config file ({}) is missing, running subset of tests'.format(config_file))
+
+    tests_pattern = os.environ.get('OPENCV_PYTEST_FILTER', 'test_*') + '.py'
+    if tests_pattern != 'test_*.py':
+        print('Tests filter: {}'.format(tests_pattern))
+
+    processed = set()
+    for l in locations:
+        if not os.path.isabs(l):
+            l = os.path.normpath(os.path.join(cwd, l))
+        if l in processed:
+            continue
+        processed.add(l)
+        print('Discovering python tests from: {}'.format(l))
+        sys_path_modify = l not in sys.path
+        if sys_path_modify:
+            sys.path.append(l)  # Hack python loader
+        discovered_tests = loader.discover(l, pattern=tests_pattern, top_level_dir=l)
+        print('    found {} tests'.format(discovered_tests.countTestCases()))
+        tests.addTests(loader.discover(l, pattern=tests_pattern))
+        if sys_path_modify:
+            sys.path.remove(l)
+    return tests
+
+if __name__ == '__main__':
+    NewOpenCVTests.bootstrap()