New script: Mylar3 LXC (#554)

* Add new LXC: Mylar3

* Apply suggestions from code review

The rest of the suggestions will be addressed in my local repo and pushed back

Co-authored-by: Håvard Gjøby Thom <34199185+havardthom@users.noreply.github.com>

* Additional changes based on the code review

* The application is no longer updatable via the user interface

---------

Co-authored-by: Håvard Gjøby Thom <34199185+havardthom@users.noreply.github.com>

install/mylar3-install.sh

@@ -0,0 +1,68 @@
+#!/usr/bin/env bash
+
+# Copyright (c) 2021-2024 community-scripts ORG
+# Author: davalanche
+# License: MIT
+# https://github.com/community-scripts/ProxmoxVE/raw/main/LICENSE
+# Source: https://github.com/mylar3/mylar3
+
+source /dev/stdin <<< "$FUNCTIONS_FILE_PATH"
+color
+verb_ip6
+catch_errors
+setting_up_container
+network_check
+update_os
+
+msg_info "Installing Dependencies"
+$STD apt-get install -y \
+  curl \
+  sudo \
+  mc \
+  jq
+echo "deb http://deb.debian.org/debian bookworm non-free non-free-firmware" > /etc/apt/sources.list.d/non-free.list
+$STD apt-get update
+$STD apt-get install -y unrar
+rm /etc/apt/sources.list.d/non-free.list
+msg_ok "Installed Dependencies"
+
+msg_info "Updating Python3"
+$STD apt-get install -y python3-pip
+rm -rf /usr/lib/python3.*/EXTERNALLY-MANAGED
+$STD pip install -U --no-cache-dir pip
+msg_ok "Updated Python3"
+
+msg_info "Installing ${APPLICATION}"
+mkdir -p /opt/mylar3
+mkdir -p /opt/mylar3-data
+RELEASE=$(curl -s https://api.github.com/repos/mylar3/mylar3/releases/latest | jq -r '.tag_name')
+wget -qO- https://github.com/mylar3/mylar3/archive/refs/tags/${RELEASE}.tar.gz | tar -xz --strip-components=1 -C /opt/mylar3
+$STD pip install --no-cache-dir -r /opt/mylar3/requirements.txt
+echo "${RELEASE}" > /opt/${APPLICATION}_version.txt
+msg_ok "Installed ${APPLICATION}"
+
+msg_info "Creating Service"
+cat <<EOF >/etc/systemd/system/mylar3.service
+[Unit]
+Description=Mylar3 Service
+After=network-online.target
+
+[Service]
+ExecStart=/usr/bin/python3 /opt/mylar3/Mylar.py --daemon --nolaunch --datadir=/opt/mylar3-data
+GuessMainPID=no
+Type=forking
+Restart=on-failure
+
+[Install]
+WantedBy=multi-user.target
+EOF
+systemctl enable -q --now mylar3.service
+msg_ok "Created Service"
+
+motd_ssh
+customize
+
+msg_info "Cleaning up"
+$STD apt-get -y autoremove
+$STD apt-get -y autoclean
+msg_ok "Cleaned"