ResourceFactory: Add function create(<name>)

The ConfigAwareFactory is an interface forcing "backend-type" classes to call
ResourceFactory::createResource() passing a config they got in the constructor.

That's kind of overdesigned, if the ResourceFactory wants to be something like
a service locator it's responsabilities should include object instantiation.

refs #5514

library/Icinga/Data/ResourceFactory.php

@@ -132,4 +132,15 @@ class ResourceFactory implements ConfigAwareFactory
         }
         return $resource;
     }
+
+    /**
+     * Create a resource from name
+     *
+     * @param   string  $resourceName
+     * @return  DbConnection|LdapConnection|LivestatusConnection|StatusdatReader
+     */
+    public static function create($resourceName)
+    {
+        return self::createResource(self::getResourceConfig($resourceName));
+    }
 }