add an option to allow adding a comment to iptables rules

[verybadsoldier]

Motivation for this is to allow gathering statistics (number of filtered packages/bytes) for the rules. When they have a comment, then e.g. InfluxDB/Telegraf will automatically pick them up.

[LaurenceJJones]

Hey 👋

Apologizes we missed this.

We are currently working through CrowdSec 1.6.4 release, once we have completed that we can spend some time reviewing this.

Thank you for your patience

[verybadsoldier]

Of course, no problem, thank you.