feat: add Feishu & Lark's OAuth Endpoints

[songquanpeng]

Related documentations:

1. https://open.feishu.cn/document/common-capabilities/sso/api/obtain-oauth-code?lang=en-US
2. https://open.feishu.cn/document/uAjLw4CM/ukTMukTMukTM/authentication-management/access-token/get-user-access-token?lang=en-US

FYI, Feishu (https://www.feishu.cn/) and Lark (https://www.larksuite.com/) are distinct brands offering similar collaboration tools, with Feishu serving the Chinese market and Lark focusing on international users.

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Patch Set 3:

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Patch Set 3:

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