Glowy lights - light fixtures now actually glow (#23428)

* glowy lights - makes light fixtures actually physically glow when active

* serviced the lights

* ya sure

Content.Shared/Light/SharedPoweredLightVisuals.cs

@@ -21,6 +21,7 @@ namespace Content.Shared.Light
 
     public enum PoweredLightLayers : byte
     {
-        Base
+        Base,
+        Glow
     }
 }