Replaces PowerReceiver's C# event with a ComponentMessage (#2888)

Co-authored-by: py01 <pyronetics01@gmail.com>

Content.Server/GameObjects/Components/VendingMachines/VendingMachineComponent.cs

@@ -1,4 +1,4 @@
-#nullable enable
+#nullable enable
 using System;
 using System.Collections.Generic;
 using System.Linq;
@@ -119,24 +119,24 @@ namespace Content.Server.GameObjects.Components.VendingMachines
 
             if (Owner.TryGetComponent(out PowerReceiverComponent? receiver))
             {
-                receiver.OnPowerStateChanged += UpdatePower;
                 TrySetVisualState(receiver.Powered ? VendingMachineVisualState.Normal : VendingMachineVisualState.Off);
             }
 
             InitializeFromPrototype();
         }
 
-        public override void OnRemove()
+        public override void HandleMessage(ComponentMessage message, IComponent? component)
         {
-            if (Owner.TryGetComponent(out PowerReceiverComponent? receiver))
+            base.HandleMessage(message, component);
+            switch (message)
             {
-                receiver.OnPowerStateChanged -= UpdatePower;
+                case PowerChangedMessage powerChanged:
+                    UpdatePower(powerChanged);
+                    break;
             }
-
-            base.OnRemove();
         }
 
-        private void UpdatePower(object? sender, PowerStateEventArgs args)
+        private void UpdatePower(PowerChangedMessage args)
         {
             var state = args.Powered ? VendingMachineVisualState.Normal : VendingMachineVisualState.Off;
             TrySetVisualState(state);