[feat][MGS][gateway] add support for sso/login path in addition to sso-login

[v-kkhuang]

What is the purpose of the change

Background/Problem:
Currently, the gateway module only supports the sso-login path for SSO authentication. Some systems or configurations may prefer the standard RESTful path format sso/login, but this is not currently supported, limiting integration flexibility.

Purpose of Change:
To address this problem, this PR modifies the path matching logic in the UserRestful class to support both sso-login and sso/login paths for SSO authentication.

Value/Impact:
After the change, systems can use the more standard RESTful path format sso/login for SSO authentication while maintaining backward compatibility with existing systems using sso-login.

Related issues/PRs

Related issues: close #1067
Related pr:none

Brief change log

• Add support for sso/login path in addition to existing sso-login path
• Update path matching logic in UserRestful to handle both path formats

Checklist

• I have read the Contributing Guidelines on pull requests.
• I have explained the need for this PR and the problem it solves
• I have explained the changes or the new features added to this PR
• I have added tests corresponding to this change
• I have updated the documentation to reflect this change
• I have verified that this change is backward compatible
• If this is a code change: I have written unit tests to fully verify the new behavior.

[casionone]

LGTM.