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/misc/plugin_gstreamer/CMakeLists.txt

@@ -0,0 +1,13 @@
+cmake_minimum_required(VERSION 3.5)
+
+get_filename_component(OpenCV_SOURCE_DIR "${CMAKE_CURRENT_LIST_DIR}/../../../.." ABSOLUTE)
+include("${OpenCV_SOURCE_DIR}/cmake/OpenCVPluginStandalone.cmake")
+
+# scan dependencies
+set(WITH_GSTREAMER ON)
+include("${OpenCV_SOURCE_DIR}/modules/videoio/cmake/init.cmake")
+
+set(OPENCV_PLUGIN_DEPS core imgproc imgcodecs)
+ocv_create_plugin(videoio "opencv_videoio_gstreamer" "ocv.3rdparty.gstreamer" "GStreamer" "src/cap_gstreamer.cpp")
+
+message(STATUS "Using GStreamer: ${GSTREAMER_VERSION}")

3rdparty/opencv-4.5.4/modules/videoio/misc/plugin_gstreamer/Dockerfile

@@ -0,0 +1,13 @@
+FROM ubuntu:18.04
+
+RUN apt-get update && apt-get --no-install-recommends install -y \
+        libgstreamer-plugins-base1.0-dev \
+        libgstreamer-plugins-good1.0-dev \
+        libgstreamer1.0-dev \
+        cmake \
+        g++ \
+        ninja-build \
+    && \
+    rm -rf /var/lib/apt/lists/*
+
+WORKDIR /tmp

3rdparty/opencv-4.5.4/modules/videoio/misc/plugin_gstreamer/build.sh

@@ -0,0 +1,11 @@
+#!/bin/bash
+
+set -e
+
+cmake -GNinja \
+    -DOPENCV_PLUGIN_NAME=opencv_videoio_gstreamer \
+    -DOPENCV_PLUGIN_DESTINATION=$1 \
+    -DCMAKE_BUILD_TYPE=$2 \
+    /opencv/modules/videoio/misc/plugin_gstreamer
+
+ninja