Handle step up authentication for when sign in again when you already have a session

[Sachin-Mamoru]

Describe the issue:
Perform acr based [1] step up authentication when you already have a session.
If a user already log in to an application and if he needs to step up the authentication, then we need to be able to invoke the sign in using through the app again.
This was blocked due to an basic user [2] [3] info check in the sign in method.

[1] https://is.docs.wso2.com/en/latest/guides/authentication/conditional-auth/acr-based-adaptive-auth/
[2] https://github.com/asgardeo/asgardeo-auth-spa-sdk/blob/3b874cdb57f203cb006e407c9ad899d0e59813fc/lib/src/clients/main-thread-client.ts#L199
[3] https://github.com/asgardeo/asgardeo-auth-js-core/blob/9769b04bd5fb274d21a8c59ebf8318933e896a1b/lib/src/core/authentication-core.ts#L629

[pavinduLakshan]

@Sachin-Mamoru can u please confirm if this issue is still reproducible?