Even more widget fixes/improvements (#9561)

* Device Summary: don't count deleted ports

* General: prevent widget refresh while in settings (synchronize "show_settings" between frontend and backend)

* General: reduce reload flicker by delaying clearing of old content until the backend is complete.

* Port Select: exclude deleted and orphaned ports

app/Http/Controllers/Select/PortController.php

@@ -62,6 +62,8 @@ class PortController extends SelectController
     {
         /** @var \Illuminate\Database\Eloquent\Builder $query */
         $query = Port::hasAccess($request->user())
+            ->isNotDeleted()
+            ->has('device')
             ->with(['device' => function ($query) {
                 $query->select('device_id', 'hostname', 'sysName');
             }])