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/gapi/doc/slides/get_sty.sh

@@ -0,0 +1,25 @@
+#!/usr/bin/env bash
+
+set -e
+
+MTHEME_VER=2fa6084b9d34fec9d2d5470eb9a17d0bf712b6c8
+MTHEME_DIR=mtheme.sty
+
+function make_sty {
+    if [ -d "$MTHEME_DIR" ]; then rm -rf "$MTHEME_DIR"; fi
+    mkdir "$MTHEME_DIR"
+
+    # Download template from Github
+    tmp_dir=$(mktemp -d)
+    wget -P "$tmp_dir" -c https://github.com/matze/mtheme/archive/${MTHEME_VER}.tar.gz
+    pushd "$tmp_dir"
+    tar -xzvf "$MTHEME_VER.tar.gz"
+    popd
+    make -C "$tmp_dir"/mtheme-"$MTHEME_VER"
+    cp   -v "$tmp_dir"/mtheme-"$MTHEME_VER"/*.sty "$MTHEME_DIR"
+    rm -r "$tmp_dir"
+    # Put our own .gitignore to ignore this directory completely
+    echo "*" > "$MTHEME_DIR/.gitignore"
+}
+
+make_sty