pkg-ubuntu: add build pipeline Ubuntu 22.04, 24.04

This commit add necessary files for building debian .deb package and
shell script to build for Ubuntu 22.04 and 24.04. You can use it by
running `extras/packaging/build_packages.sh` script.

Change-Id: I91ba97cbe932ff4207072dcb2f9d2b2887de236a
diff --git a/build_tar_gz.sh b/build_tar_gz.sh
new file mode 100755
index 0000000..dacbc04
--- /dev/null
+++ b/build_tar_gz.sh
@@ -0,0 +1,29 @@
+#!/bin/bash
+PKG_NAME=dhtnet
+PKG_VERSION=0.2.0
+
+FOLDER_NAME="${PKG_NAME}-${PKG_VERSION}"
+
+rm -Rf "${FOLDER_NAME}"
+rm -f "${PKG_NAME}-${PKG_VERSION}.tar.gz"
+mkdir -p "${FOLDER_NAME}"
+
+git submodule update --init --recursive
+
+# copy source code
+cp -Rf dependencies "${FOLDER_NAME}/dependencies"
+cp -Rf include "${FOLDER_NAME}/include"
+cp -Rf src "${FOLDER_NAME}/src"
+cp -Rf tools "${FOLDER_NAME}/tools"
+cp -Rf CMakeLists.txt "${FOLDER_NAME}/CMakeLists.txt"
+cp -Rf COPYING "${FOLDER_NAME}/COPYING"
+cp -Rf dhtnet.pc.in "${FOLDER_NAME}/dhtnet.pc.in"
+cp -Rf README.md "${FOLDER_NAME}/README.md"
+
+# copy debian conf
+cp -Rf "extras/packaging/gnu-linux/debian" "${FOLDER_NAME}/debian"
+
+tar -czf "${PKG_NAME}-${PKG_VERSION}.tar.gz" "${FOLDER_NAME}"
+
+echo "Archive ${PKG_NAME}-${PKG_VERSION}.tar.gz is ready"
+echo "Use   tar -xzf ${PKG_NAME}-${PKG_VERSION}.tar.gz   to unzip this file and package it with debuild"