Fix return function name span

src/MessageStudio/Formats/BinaryText/Components/FunctionMap.cs

@@ -197,7 +197,7 @@ private static ReadOnlySpan<char> GetFunctionName(in ReadOnlySpan<char> text, ou
                     """);
             }
 
-            return text[1..paramsStartIndex++];
+            return text[2..paramsStartIndex++];
         }
         else {
             leadingByte = 0xE;