light refactoring/rework (#19314)

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

Content.Shared/Light/Components/RgbLightControllerComponent.cs

@@ -0,0 +1,57 @@
+using Robust.Shared.GameStates;
+using Robust.Shared.Serialization;
+
+namespace Content.Shared.Light.Components;
+
+/// <summary>
+///     Makes the color of lights on an entity fluctuate. Will update point-light color and modulate some or all of the
+///     sprite layers. Will also modulate the color of any unshaded layers that this entity contributes to a wearer or holder.
+/// </summary>
+/// <remarks>
+///     Networked ~~solely for admemes~~ for completely legitimate reasons, like hacked energy swords.
+/// </remarks>
+[NetworkedComponent, RegisterComponent, Access(typeof(SharedRgbLightControllerSystem))]
+public sealed partial class RgbLightControllerComponent : Component
+{
+    [DataField("cycleRate")]
+    public float CycleRate { get; set; } = 0.1f;
+
+    /// <summary>
+    ///     What layers of the sprite to modulate? If null, will affect only unshaded layers.
+    /// </summary>
+    [DataField("layers")]
+    public List<int>? Layers;
+
+    /// <summary>
+    ///     Original light color from befor the rgb was aded. Used to revert colors when removed.
+    /// </summary>
+    public Color OriginalLightColor;
+
+    /// <summary>
+    ///     Original colors of the sprite layersfrom before the rgb was added. Used to revert colors when removed.
+    /// </summary>
+    public Dictionary<int, Color>? OriginalLayerColors;
+
+    /// <summary>
+    ///     User that is holding or wearing this entity
+    /// </summary>
+    public EntityUid? Holder;
+
+    /// <summary>
+    ///     List of unshaded layers on the holder/wearer that are being modulated.
+    /// </summary>
+    public List<string>? HolderLayers;
+}
+
+[Serializable, NetSerializable]
+public sealed class RgbLightControllerState : ComponentState
+{
+    public readonly float CycleRate;
+    public List<int>? Layers;
+
+    public RgbLightControllerState(float cycleRate, List<int>? layers)
+    {
+        CycleRate = cycleRate;
+        Layers = layers;
+    }
+}