light refactoring/rework (#19314)

Co-authored-by: deltanedas <@deltanedas:kde.org>

Content.Shared/Light/Components/SharedLightBehaviourComponent.cs

@@ -0,0 +1,8 @@
+namespace Content.Shared.Light.Components;
+
+/// <summary>
+/// A component which applies a specific behaviour to a PointLightComponent on its owner.
+/// </summary>
+public abstract partial class SharedLightBehaviourComponent : Component
+{
+}