Port NBT impl from LibAC Dart

NBT/API/NBTAccountant.cs

@@ -0,0 +1,32 @@
+namespace LibAC.NBT.API;
+
+using System;
+
+public class NBTAccountant
+{
+    private static int _prettyIndex = 0;
+
+    public static void PrintRead(Tag tag)
+    {
+        tag.PrettyPrint(_prettyIndex, false);
+    }
+
+    public static void VisitTag()
+    {
+        _prettyIndex++;
+    }
+
+    public static void LeaveTag(Tag tag)
+    {
+        if (tag is CompoundTag ct)
+        {
+            ct.EndPrettyPrint(_prettyIndex);
+        }
+        else if (tag is ListTag lt)
+        {
+            lt.EndPrettyPrint(_prettyIndex);
+        }
+
+        _prettyIndex--;
+    }
+}