[WIP] Add deep_ep_wrapper to support SGLang or other frameworks

[whn09]

Description

SGLang use from deep_ep import Buffer, Config to call DeepEP, and to make uccl.ep compatible with SGLang, I add the deep_ep_wrapper. But the code has bugs now, especially with Buffer, because we should call initialize_uccl in Buffer.

Fixes # (issue)

Type of Change

• Bug fix
• New feature
• Documentation update

How Has This Been Tested?

Include any tests here.

• Unit tests
• Integration tests
• Manual testing

Checklist

• My code follows the style guidelines, e.g. format.sh.
• I have run build_and_install.sh to verify compilation.
• I have removed redundant variables and comments.
• I have updated the documentation.
• I have added tests.

[YangZhou1997]

@whn09 , thank you for the contribution. I think we have buffer.py and utils.py inside bench. So we should probably create an ep folder, and put buffer.py, utils.py, and init.py there, minicking the deepep manner. cc @MaoZiming @CalebZ9909

[MaoZiming]

Just want to let you know that these two PRs might help with the porting
#490
#491