support for modelscope gradio

[qbc2016]

Description

This pr implements the presentation of the gradio interface.
For example,
run python examples/conversation/conversation.py will chat in the terminal interface,
run as_studio examples/conversation/conversation.py will launch a studio interface.
Usage:
run as_studio path/to/your/script.py
Remark:
There should be a main() function in your script.py which is got run

Checklist

Please check the following items before code is ready to be reviewed.

• Code has passed all tests
• Docstrings have been added/updated in Google Style
• Documentation has been updated
• Code is ready for review

[rayrayraykk]

Please add the following codes in setup.py:

setuptools.setup(
    # ... 
    entry_points={
        'console_scripts': [
            'agentscope_ui=agentscope.web_ui.app:main',
        ],
    },
    # ... 
)

So that the user can run with shorter commands agentscope_ui --script ooxx

[rayrayraykk]

Please see the inline comments.

[rayrayraykk]

Please check the usability in win OS, and other part looks good to me.

[DavdGao]

LGTM, in the future we should merge all web UI into one web interface.