more component ref removal + combining server/client comps (#13178)

Co-authored-by: DrSmugleaf <DrSmugleaf@users.noreply.github.com>

Content.Shared/Flash/FlashableComponent.cs

@@ -0,0 +1,27 @@
+using Robust.Shared.GameStates;
+using Robust.Shared.Serialization;
+
+namespace Content.Shared.Flash
+{
+    [RegisterComponent, NetworkedComponent]
+    public sealed class FlashableComponent : Component
+    {
+        public float Duration;
+        public TimeSpan LastFlash;
+
+        public override bool SendOnlyToOwner => true;
+    }
+
+    [Serializable, NetSerializable]
+    public sealed class FlashableComponentState : ComponentState
+    {
+        public float Duration { get; }
+        public TimeSpan Time { get; }
+
+        public FlashableComponentState(float duration, TimeSpan time)
+        {
+            Duration = duration;
+            Time = time;
+        }
+    }
+}