This opens TCP port 22 on all hosts, TCP ports 80 and 443 on hosts
in the web group, and allows configuration of "extra" rules in the
host or group vars.
I will try using nftables directly instead of via firewalld as of
Debian 11 as it is the replacement for the iptables/ipset stack in
recent years and is easier to work with.
This also includes a systemd service, timer, and script to update
the spamhaus DROP lists as nftables sets.
Still need to add fail2ban support.