List users which are oauth enabled

### The required feature described as a wish

As a User/Admin/Operator I would like to list the users which have Ouath enabled

Steps to reproduce the issue

1. Configure Oauth

https://docs.cloudstack.apache.org/en/4.22.0.0/adminguide/accounts.html#using-oauth2-authentication-for-users

2. Create a user account which has the email configured with the oauth provider

3. Login with Oauth

4. Oauth successful

Currently, we can list the users based on usersource

https://cloudstack.apache.org/api/apidocs-4.22/apis/listUsers.html

usersource
List users by their authentication source. Valid values are: native, ldap, saml2 and saml2disabled.

It would nice if we can add Oauth to it

先从 issue 中链接的 listUsers API 文档和 OAuth2 身份验证指南开始，然后追踪现有 usersource 过滤器如何处理 native、LDAP 和 SAML 用户。完成的标准是 listUsers 能够通过 OAuth 值识别启用了 OAuth 的用户，并且 API 文档描述该值。

由索引模型根据 Issue 内容生成。