Remove debug globals (#12811)

* Remove $debug global
and $vdebug global
makes these variables more accessible and protects from collisions.

* the on boot set sends application as the first parameter, just handle that

* Relocate other debug related functions

* Log debug to stdout

* Wrong output

* remove stupid constants

* Fix lint and style issues

alerts.php

@@ -28,13 +28,14 @@
  */
 
 use LibreNMS\Alert\RunAlerts;
+use LibreNMS\Util\Debug;
 
 $init_modules = ['alerts', 'laravel'];
 require __DIR__ . '/includes/init.php';
 
 $options = getopt('d::');
 
-if (set_debug(isset($options['d']))) {
+if (Debug::set(isset($options['d']))) {
     echo "DEBUG!\n";
 }