Evaluate WebWand on the WebArena dataset

[lingjiefeng]

Use WebArena benchmark.

1. Setup the standalone environment of WebArena
2. Configurate the urls for each website.
3. Generate config file for each test example and obtain the auto-login cookies for all websites
4. Write script to use WebArena's environment based on its run.py
5. Save task execution results and evaluate.
6. Analyze the evaluation results