Removes all dependencies on engine component events. (#4199)

Content.Client/Alerts/ClientAlertsSystem.cs

@@ -0,0 +1,16 @@
+using Robust.Client.GameObjects;
+using Robust.Shared.GameObjects;
+
+namespace Content.Client.Alerts
+{
+    internal class ClientAlertsSystem : EntitySystem
+    {
+        public override void Initialize()
+        {
+            base.Initialize();
+
+            SubscribeLocalEvent<ClientAlertsComponent, PlayerAttachedEvent>((_, component, _) => component.PlayerAttached());
+            SubscribeLocalEvent<ClientAlertsComponent, PlayerDetachedEvent>((_, component, _) => component.PlayerDetached());
+        }
+    }
+}