Implements Local Host behaviour analysis and it's alert

Alert in case the host has an unexpected behaviour

scripts/plugins/alerts/security/unexpected_host_behaviour/manifest.lua

@@ -0,0 +1,10 @@
+--
+-- (C) 2019-21 - ntop.org
+--
+
+return {
+  title = "Unexpected Host Behaviour",
+  description = "Detects if an host contacts an unexpected number of domains",
+  author = "ntop",
+  dependencies = {},
+}