Update webui.py with username and password

[natarajan0007]

During the demo, we may demonstrate parsing usernames and passwords, which are currently displayed in plain text in the UI using task descriptions. By implementing this change, users can select the credentials required for their website's login process. However, please note that this does not prevent sensitive data from appearing in the console logs. It's a good approach for getting started initially.

[warmshao]

This is a bit too customized and not universal enough. For example, what should I do if I have multiple accounts and passwords? Or for other types of sensitive data, I think we need to come up with a more universal way.

[pksorensen]

My solution solves the same problem #316

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