Decouple Lights from Toggleable Visuals (and headphone music notes bugfix) (#35341)

* - Combine enum keys `ToggleableLightVisuals` and `ToggleVisuals` into `ToggleableVisuals`
- Rename `ToggleableLightVisualsComponent` to `ToggleableVisualsComponent` and `ToggleableLightVisualsSystem` to `ToggleableVisualsSystem`
  - (The `SpriteLayer` field on the component is now required because the old default of `light` doesn't make sense anymore)
- Make it so that `ToggleableVisualsComponent` works even when there's not a light attached to the entity
  - (Amazingly this seems to have only applied to  Headphones, but I can only imagine there are many other things people would like to do with simple toggleable visuals)
- Explicitly make `ItemTogglePointLightComponent`'s purpose to make `ToggleVisualsComponent` apply to `PointLightComponent`s on the same entity.
  - Add field `ToggleableVisualsColorModulatesLights`, which makes the `Color` appearance value of `ToggleableVisuals` modulate the color of lights on the same entity
  - Lots of prototype updates to uptake the above

* fix bad merge

* unbork robust

* blindly letting rider reformat stuff

* I guess I never cleaned up these imports at all

Content.Shared/ContainerHeld/ContainerHeldSystem.cs

@@ -32,12 +32,12 @@ public sealed class ContainerHeldSystem : EntitySystem
         if (_storage.GetCumulativeItemAreas(uid) >= comp.Threshold)
         {
             _item.SetHeldPrefix(uid, "full", component: item);
-            _appearance.SetData(uid, ToggleVisuals.Toggled, true, appearance);
+            _appearance.SetData(uid, ToggleableVisuals.Enabled, true, appearance);
         }
         else
         {
             _item.SetHeldPrefix(uid, "empty", component: item);
-            _appearance.SetData(uid, ToggleVisuals.Toggled, false, appearance);
+            _appearance.SetData(uid, ToggleableVisuals.Enabled, false, appearance);
         }
     }
 }