Reworks plugin loading and structure

Implements #4358

scripts/plugins/examples/example/ts_schemas/5mins.lua

@@ -0,0 +1,21 @@
+--
+-- (C) 2020 - ntop.org
+--
+
+-- This file contains timeseries defintions which have 5 minutes granularity
+
+local ts_utils = require "ts_utils_core"
+local schema
+
+-- Define a schema "host:total_hops" as a counter (suitable for
+-- cumulative values).
+schema = ts_utils.newSchema("host:total_hops", {
+  step = 300,
+  metrics_type = ts_utils.metrics.counter,
+})
+
+-- The record identifiers
+schema:addTag("ifid")
+schema:addTag("host")
+-- The values
+schema:addMetric("num_hops")