feat(refresh token): Add refresh token to the credential dictionary

[MarkusDressel]

Hi,
thanks for the great work making OIDC available in streamlit.
I would like to request to add the refresh token (if requested and available) also to the credentials.
I see already in the local session storage (Browser), that when requesting offline_access scope, the respective refresh token is already stored in the storage but it is not passed through the object in streamlit/python.

This is very important to have for example changing the scope of the token from the frontend or get a new token in case the old one is expired. Should also not hard to be implemented since MSAL is already successfully writing it in the session storage.

Related issues:
#9

[mstaal]

Hi @MarkusDressel ! I hope to be able to look into this soon - I appreciate your comment. Hopefully, I can soon give this some additional work.

[javierpinaedison]

Hi @mstaal , I am interested in this feature, as well.