Many lighting tweaks (#4709)

Content.Server/Light/Components/LitOnPoweredComponent.cs

@@ -0,0 +1,18 @@
+using Content.Server.Light.EntitySystems;
+using Robust.Shared.Analyzers;
+using Robust.Shared.GameObjects;
+
+namespace Content.Server.Light.Components
+{
+    // TODO PoweredLight also snowflakes this behavior. Ideally, powered light is renamed to 'wall light' and the
+    // actual 'light on power' stuff is just handled by this component.
+    /// <summary>
+    ///     Enables or disables a pointlight depending on the powered
+    ///     state of an entity.
+    /// </summary>
+    [RegisterComponent, Friend(typeof(PoweredLightSystem))]
+    public class LitOnPoweredComponent : Component
+    {
+        public override string Name => "LitOnPowered";
+    }
+}