Fix popup toast messages (Remove Flasher) (#16090)

* Remove flasher
Just use a bit of custom code to interface with toastr js
This is able to retain our custom theme and work properly

* Fix style issues

* Missed reference rename

* Remove test code :)

* Fix a missed rename

* Fix one more missed reference

* Fix typo

config/flasher.php

@@ -1,21 +0,0 @@
-<?php
-
-return [
-    'default' => 'template.librenms',
-
-    'root_script' => null,
-
-    'template_factory' => [
-        'templates' => [
-            'librenms' => [
-                'view' => 'layouts.flasher-notification',
-                'options' => [
-                    'timeout' => 12000,
-                    'style' => [
-                        'top' => '55px',
-                    ],
-                ],
-            ],
-        ],
-    ],
-];