support for keycloak 25.0.2

[milesjoe09]

currently this service doesn't work with keycloak 25 due to a deprecation of authServerUrl and authUrl in favor of serverBaseUrl
there are also changes in tokens.

https://www.keycloak.org/docs/latest/upgrading/index.html#deprecated-theme-variables

https://www.keycloak.org/docs/latest/upgrading/index.html#removing-deprecated-methods-from-accesstoken-idtoken-and-jsonwebtoken-classes

[NikiforovAll]

Could you please elaborate? Do you have an example somewhere? I don't think these changes may impact the library itself, looks like changes in Urls are related to theming