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.Server/GameObjects/EntitySystems/ExpendableLightSystem.cs

@@ -0,0 +1,18 @@
+
+using JetBrains.Annotations;
+using Robust.Shared.GameObjects.Systems;
+using Content.Server.GameObjects.Components.Interactable;
+
+namespace Content.Server.GameObjects.EntitySystems
+{
+    public class ExpendableLightSystem : EntitySystem
+    {
+        public override void Update(float frameTime)
+        {
+            foreach (var light in ComponentManager.EntityQuery<ExpendableLightComponent>())
+            {
+                light.Update(frameTime);
+            }
+        }
+    }
+}