Refactors alerts and flow statuses in builtin and plugins

Implements #3811
Implements #3812

Refactors builtin alerts

Refactors builtin flow statuses

scripts/lua/modules/alert_definitions/alert_new_device.lua

@@ -0,0 +1,21 @@
+--
+-- (C) 2019-20 - ntop.org
+--
+
+local alert_keys = require "alert_keys"
+
+local function formatNewDeviceConnectionAlert(ifid, alert, info)
+  return(i18n("alert_messages.a_new_device_has_connected", {
+    device = info.device,
+    url = getMacUrl(alert.alert_entity_val),
+  }))
+end
+
+-- #######################################################
+
+return {
+  alert_key = alert_keys.ntopng.alert_new_device,
+  i18n_title = "alerts_dashboard.new_device",
+  i18n_description = formatNewDeviceConnectionAlert,
+  icon = "fas fa-asterisk",
+}