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/Light/EntitySystems/ItemTogglePointLightSystem.cs

@@ -1,16 +1,15 @@
 using Content.Shared.Item.ItemToggle.Components;
 using Content.Shared.Light.Components;
-using Content.Shared.Toggleable;
 using ItemTogglePointLightComponent = Content.Shared.Light.Components.ItemTogglePointLightComponent;
 
 namespace Content.Shared.Light.EntitySystems;
 
 /// <summary>
-/// Handles ItemToggle for PointLight
+/// Implements the behavior of <see cref="ItemTogglePointLightComponent"/>, causing <see cref="ItemToggledEvent"/>s to
+/// enable and disable lights on the entity.
 /// </summary>
 public sealed class ItemTogglePointLightSystem : EntitySystem
 {
-    [Dependency] private readonly SharedAppearanceSystem _appearance = default!;
     [Dependency] private readonly SharedPointLightSystem _light = default!;
     [Dependency] private readonly SharedHandheldLightSystem _handheldLight = default!;
 
@@ -25,7 +24,6 @@ public sealed class ItemTogglePointLightSystem : EntitySystem
         if (!_light.TryGetLight(ent.Owner, out var light))
             return;
 
-        _appearance.SetData(ent, ToggleableLightVisuals.Enabled, args.Activated);
         _light.SetEnabled(ent.Owner, args.Activated, comp: light);
         if (TryComp<HandheldLightComponent>(ent.Owner, out var handheldLight))
         {