Refactor eloquent base (#9716)

* extract PortRelatedModel and DeviceRelatedModel

* add scope for inDeviceGroup

* handle null device group

app/Models/Ipv4Mac.php

@@ -2,10 +2,15 @@
 
 namespace App\Models;
 
-use Illuminate\Database\Eloquent\Model;
-
-class Ipv4Mac extends Model
+class Ipv4Mac extends PortRelatedModel
 {
     protected $table = 'ipv4_mac';
     public $timestamps = false;
+
+    // ---- Define Relationships ----
+
+    public function device()
+    {
+        return $this->belongsTo('App\Models\Device', 'device_id');
+    }
 }