Fix item delete in own inventory

Dragging items across top and bottom inventories with own inventory open resulted in the overlapping content being deleted.

plugin/src/main/java/com/lishid/openinv/internal/IPlayerDataManager.java

@@ -54,6 +54,18 @@ public interface IPlayerDataManager {
     @Nullable
     InventoryView openInventory(@NotNull Player player, @NotNull ISpecialInventory inventory);
 
+    /**
+     * Convert a raw slot number into a player inventory slot number.
+     *
+     * <p>Note that this method is specifically for converting an ISpecialPlayerInventory slot number into a regular
+     * player inventory slot number.
+     *
+     * @param view the open inventory view
+     * @param rawSlot the raw slot in the view
+     * @return the converted slot number
+     */
+    int convertToPlayerSlot(InventoryView view, int rawSlot);
+
     void sendSystemMessage(@NotNull Player player, @NotNull String message);
 
     @NotNull