Glowsticks, flares and lighting behaviours (#1886)

* Assets

* LightingBehaviours, flares, and such.

* More changes

* More changes, more flare work.

* More work on flares + light behaviours

* another refactor

* missed

* Light behaviours refactor, added sfx, improved graphics, improved lighting effects for glowstick and flare.

* remove unneeded value

* nullables

* remove old code

* nullable

* one last push

* net id

* more work

* more colors for glowsticks

* Adjust flare so it fades in

* fix name

* sprite fix

Content.Shared/GameObjects/Components/SharedLightBehaviourComponent.cs

@@ -0,0 +1,13 @@
+
+using Robust.Shared.GameObjects;
+
+namespace Content.Shared.GameObjects.Components
+{
+    /// <summary>
+    /// A component which applies a specific behaviour to a PointLightComponent on its owner.
+    /// </summary>
+    public class SharedLightBehaviourComponent : Component 
+    {
+        public override string Name => "LightBehaviour";
+    }
+}