(ids) add template for user defined rule settings

src/opnsense/service/templates/OPNsense/IDS/+TARGETS

 rc.conf.d:/etc/rc.conf.d/suricata
+rules.config:/usr/local/etc/suricata/rules.config

src/opnsense/service/templates/OPNsense/IDS/rules.config

+#
+# OPNsense suricata rule template, this configuration will be used together with all installed
+# rules to generate the desired ruleset for OPNsense.
+#
+{% if helpers.exists('OPNsense.IDS.rules.rule') %}
+{%      for rule in helpers.toList('OPNsense.IDS.rules.rule') %}
+[rule_{{rule.sid|default('0')}}]
+enabled={{ rule.enabled|default('0') }}
+
+{%      endfor %}
+{% endif %}