[keycloak-dev] Remove kcinit and text-based authentication flows

kcinit and it's associated text-based authentication flows adds quite a bit of complexity. It was never fully completed and we don't have capacity to complete it. Text-based authentication flows are also not really all that useful. There are other better approaches to authenticate devices without a web browser, and when there is a web browser that should be used rather than cli. I propose we remove both kcinit as well as the text-based authentication flows. We also need to revert KeycloakInstalled to how it was prior to this was added as it is currently fairly broken.