zabbix_agentd: Add IPS throughput and guardian blocked IP count items
- Adds Zabbix Agent userparameter `ipfire.ips.throughput.get` for the agent to get details about IPS throughput bypassed/scanned/whitelisted in bytes (JSON)
- Adds Zabbix Agent userparameter `ipfire.guardian.blocked.count` for the agent to get the number of currently blocked IP's by Addon: Guardian.
Signed-off-by: Robin Roevens <robin.roevens@disroot.org> Signed-off-by: Arne Fitzenreiter <arne_f@ipfire.org>