Add raw accessibility-tree based prompting method (but the tokens are too large); Minor fix some small bugs

desktop_env/evaluators/metrics/general.py

@@ -4,7 +4,7 @@ import functools
 import operator
 import re
 from numbers import Number
-from typing import Callable, Any
+from typing import Callable, Any, Union
 from typing import Dict, List, Pattern
 
 import lxml.etree