Ui improvements

see https://github.com/theforeman/staypuft/wiki/UI-Parameters-for-new-wizard
cc @sseago 
**NOT READY**
The short answer is "this is what astapor does." I think the value there in the model where users see the full param screens is that it's easy to just replace the IP addr with what you want than trying to remember the full format. However, with our new approach here with UI params, presumably most of these need to be included in the set of params that we dynamically fill in IP addresses.