Enhacement #1: Track security updates

[AkuLink1]

Some packages are marked as security updates, which would be useful to categorize in its own category and show an alert in the Server Template name.

https://serverfault.com/questions/424486/how-to-get-a-list-of-security-updates-on-the-command-line-in-debian-ubuntu

• Zabbix Template 1: Add a new item in Zabbix template
• Zabbix Template 2: Change trigger so that trigger name shows which of the updates are security updates
• Agent script 3: Grep the field in apt-upgrade -s output (security might not be enough, maybe grep by Debian-Security) and send to Zabbix server