Fix mis-reading byte-order

Author: ArchLeaders

src/MessageStudio/Formats/BinaryText/ImmutableMsbt.cs

@@ -41,7 +41,7 @@ public ImmutableMsbt(ref RevrsReader reader)
         if (header.ByteOrderMark is Endianness.Little) {
             // Reverse the buffer back to LE
             // since it's initially read in BE
-            reader.Reverse<MsbtHeader, MsbtHeader.Reverser>(0);
+            reader.Reverse<MsbtHeader, MsbtHeader.DataReverser>(0);
             reader.Endianness = Endianness.Little;
         }
 

src/MessageStudio/Formats/BinaryText/Structures/MsbtHeader.cs

@@ -47,4 +47,18 @@ public static void Reverse(in Span<byte> buffer)
             buffer[0x12..0x16].Reverse();
         }
     }
+
+    /// <summary>
+    /// Reverser for only the data,
+    /// the BoM is not reversed
+    /// </summary>
+    public class DataReverser : IStructReverser
+    {
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void Reverse(in Span<byte> buffer)
+        {
+            buffer[0x0E..0x10].Reverse();
+            buffer[0x12..0x16].Reverse();
+        }
+    }
 }