Add event publishing for inventory and combat interactions

GameCore/Events/WeaponEquippedEvent.cs

@@ -0,0 +1,10 @@
+using GameCore.ECS;
+using GameCore.Events.Interfaces;
+
+namespace GameCore.Events;
+
+public readonly struct WeaponEquippedEvent(Entity owner, string newWeaponItemId) : IEvent
+{
+    public readonly Entity Owner = owner;
+    public readonly string NewWeaponItemId = newWeaponItemId;
+}