Add weapon acquisition and swapping systems with data handling

GameCore/Events/EquipWeaponEvent.cs

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