Add MPLS Support (#10263)

* WIP - Add MPLS Support
This introduce the generic MPLS support
- New database tables for MPLS LSPs
- actually discovery and polling on NOKIA SR OS (Timetra) devices
- new routing->MPLS HTML pages

- ToDo MPLS LSP paths table and views
Suggestions and improvements are welcome

* add db schema

* some fixes

* add path table, discovery and polling

* add path views

* add test data

* Convert MPLS module to new style
Implement a SyncsModels trait to simplify code a lot

* abs() for negative value from snmp (bug?), test data

* fix db schema

* Fix up test data, remove uneeded data in json

* fix whitespace

LibreNMS/Util/ModuleModelObserver.php

@@ -26,9 +26,24 @@
 namespace LibreNMS\Util;
 
 use Illuminate\Database\Eloquent\Model as Eloquent;
+use Illuminate\Support\Str;
 
 class ModuleModelObserver
 {
+    /**
+     * Install observers to output +, -, U for models being created, deleted, and updated
+     *
+     * @param string $model The model name including namespace
+     */
+    public static function observe($model)
+    {
+        $model = Str::start($model, '\\');
+        // discovery output (but don't install it twice (testing can can do this)
+        if (!$model::getEventDispatcher()->hasListeners('eloquent.created: ' . ltrim('\\', $model))) {
+            $model::observe(new ModuleModelObserver());
+        }
+    }
+
     public function saving(Eloquent $model)
     {
         if (!$model->isDirty()) {