Make flashlights, atmos hardsuit, and RGB use the new layer features (#6253)

* Make flashlights, atmos hardsuit, and RGB use the new layer features

* avoid self-conflict

* fix rgb not updating on add

* cleanup

* Update Content.Client/Light/RgbLightControllerSystem.cs

Co-authored-by: mirrorcult <lunarautomaton6@gmail.com>

* cleanup diff

Co-authored-by: mirrorcult <lunarautomaton6@gmail.com>

Content.Shared/Inventory/InventorySystem.Equip.cs

@@ -84,9 +84,6 @@ public abstract partial class InventorySystem
         if(!TryGetSlot(uid, args.Container.ID, out var slotDef, inventory: component))
            return;
 
-        // un-rotate entities. needed for things like directional flashlights on hardsuit helmets
-        Transform(args.Entity).LocalRotation = 0;
-
         var equippedEvent = new DidEquipEvent(uid, args.Entity, slotDef);
         RaiseLocalEvent(uid, equippedEvent);