suricata: Add files to be backuped

suricata: Add files to be backuped

Now all oinkmaster related config files and suricata
related yaml files in "/var/ipfire/suricata/" will be
included into the backups.

Also the entire ruleset is part of the backup, so after a
backup has been restored, the IDS can be used in the same way
as before.

Fixes #11835.

Signed-off-by: Stefan Schantl <stefan.schantl@ipfire.org>