* feat: add the ui for configuring the third-party standard OAuth2.0/OIDC.
- update SystemSetting.js
- add setup ui
- add configuration
* feat: add the ui for "allow the OAuth 2.0 to login"
- update SystemSetting.js
* feat: add OAuth 2.0 web ui and its process functions
- update common.js
- update AuthLogin.js
- update config.js
* fix: missing "Userinfo" endpoint configuration entry, used by OAuth clients to request user information from the IdP.
- update config.js
- update SystemSetting.js
* feat: updated the icons for Lark and OIDC to match the style of the icons for WeChat, EMail, GitHub.
- update lark.svg
- new oidc.svg
* refactor: Changing OAuth 2.0 to OIDC
* feat: add OIDC login method
* feat: Add support for OIDC login to the backend
* fix: Change the AppId and AppSecret on the Web UI to the standard usage: ClientId, ClientSecret.
* feat: Support quick configuration of OIDC through Well-Known Discovery Endpoint
* feat: Standardize terminology, add well-known configuration
- Change the AppId and AppSecret on the Server End to the standard usage: ClientId, ClientSecret.
- add Well-Known configuration to store in database, no actual use in server end but store and display in web ui only
- Refactor constant definitions and organization
- Clean up package level variables and functions
- Introduce new `relaymode` and `apitype` packages for constant definitions
- Refactor and simplify code in several packages including `openai`, `relay/channel/baidu`, `relay/util`, `relay/controller`, `relay/channeltype`
- Add helper functions in `relay/channeltype` package to convert channel type constants to corresponding API type constants
- Remove deprecated functions such as `ResponseText2Usage` from `relay/channel/openai/helper.go`
- Modify code in `relay/util/validation.go` and related files to use new `validator.ValidateTextRequest` function
- Rename `util` package to `relaymode` and update related imports in several packages
