Security fix: unauthorized access (#10091)

* Security fix: unauthorized access
Affects nginx users:
Moved php files outside of public html directory (Apache was protected by .htaccess)

Affects all users:
Some files did not check for authentication and could disclose some info.
Better checks before including files from user input

* git mv html/includes/ includes/html
git mv html/pages/ includes/html/

includes/html/pages/health/delay.inc.php

@@ -0,0 +1,7 @@
+<?php
+
+$graph_type = 'sensor_delay';
+$class      = 'delay';
+$unit       = 's';
+
+require 'includes/html/pages/health/sensors.inc.php';