Fix various issues with loading os definitions (#11640)

* Ping only device doesn't display
if os was set to something, ping os wasn't loaded and we try to get overview graphs from it.

* Fix snmp_disable device page load error
When other os is set.

* Revamp os setting loading
the only safe way to access is Config::getOsSetting()

* Remove getOsSetting fallback behavior
Most instances don't use it and it can have unexpected results Config::getOsSetting('blah', 'group') == 'librenms'

* refactor and remove unneeded load_os/loadOs calls now since getOsSetting automatically loads it.

* restore unix overview graphs, they are different
small cleanups

* fix

app/Http/Controllers/DeviceController.php

@@ -12,6 +12,7 @@ use Gate;
 use Illuminate\Http\Request;
 use Illuminate\Support\Arr;
 use LibreNMS\Config;
+use LibreNMS\Util\Graph;
 use LibreNMS\Util\Url;
 
 class DeviceController extends Controller
@@ -130,7 +131,7 @@ class DeviceController extends Controller
         ];
 
         $graphs = [];
-        foreach ($this->getDeviceGraphs($device) as $graph) {
+        foreach (Graph::getOverviewGraphsForDevice($device) as $graph) {
             $graph_array['type'] = $graph['graph'];
             $graph_array['popup_title'] = __($graph['text']);
             $graphs[] = $graph_array;
@@ -139,18 +140,6 @@ class DeviceController extends Controller
         return $graphs;
     }
 
-    private function getDeviceGraphs(Device $device)
-    {
-        if ($device->snmp_disable) {
-            return Config::get('os.ping.over');
-        } elseif (Config::has("os.$device->os.over")) {
-            return Config::get("os.$device->os.over");
-        }
-
-        $os_group = Config::getOsSetting($device->os, 'group');
-        return Config::get("os.$os_group.over", Config::get('os.default.over'));
-    }
-
     private function deviceLinkMenu(Device $device)
     {
         $device_links = [];