Refactor more stuff (Audio mostly)

Zennysoft.Game.Ma.Implementation/Item/EquipableItem.cs

@@ -0,0 +1,13 @@
+using Chickensoft.Introspection;
+using Chickensoft.Serialization;
+
+namespace Zennysoft.Ma.Adapter;
+
+[Meta, Id("equipable_item")]
+public abstract partial class EquipableItem : InventoryItem
+{
+  public abstract ItemTag ItemTag { get; }
+
+  [Save("equipable_item_is_equipped")]
+  public bool IsEquipped { get; set; }
+}