Singularity Shaders and a lot of Shader Stuff (#2517)

* Beginnings of singulo shader

* LOTS of changes!!

* Minor changes

* Singulo stuff

* Aesthetic changes to singulo

* Combining singulo change

* ShaderAura uses IEntities now, not IPlayerSession

* Fixes?

* Fixes draw order for atmos

* using fix

* Address reviews

* nuget.config whaaa

* nuget haha

* nuget why are you so dum

* happy now

* Preparing for omegachange

* Merge from seventh level of hell

* woork

* Ignorecomponents add

* mmf

* RobustToolbox?

* Fixes

* Fixes Robust?

* adds sprite

* Nullables

* Crit overlay stuff

* Commits Robust

Content.Client/GameObjects/Components/Weapons/FlashableComponent.cs

@@ -1,8 +1,10 @@
-using System;
+#nullable enable
+using System;
 using Content.Client.Graphics.Overlays;
 using Content.Shared.GameObjects.Components.Weapons;
 using Robust.Client.Graphics;
 using Robust.Client.Player;
+using Robust.Shared.Enums;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
 using Robust.Shared.Timing;
@@ -15,7 +17,7 @@ namespace Content.Client.GameObjects.Components.Weapons
         private TimeSpan _startTime;
         private double _duration;
 
-        public override void HandleComponentState(ComponentState curState, ComponentState nextState)
+        public override void HandleComponentState(ComponentState? curState, ComponentState? nextState)
         {
             if (curState == null)
             {
@@ -55,7 +57,7 @@ namespace Content.Client.GameObjects.Components.Weapons
             _duration = newState.Duration;
 
             var overlayManager = IoCManager.Resolve<IOverlayManager>();
-            var overlay = overlayManager.GetOverlay<FlashOverlay>(nameof(FlashOverlay));
+            var overlay = overlayManager.GetOverlay<FlashOverlay>();
             overlay.ReceiveFlash(_duration);
         }
     }