Add configuration profile for mixed authentication environments (e.g. SSO with password fallback) 

This approach was proposed by @hammertoe  #1

@hammertoe Thanks for the tip. This works for us now, but how does it look for you? Have I missed some corner cases in the challenge-js/view-part?

Currently, I added the profile into its own sub-package, because this probably should not be "the default configuration", but the profile must be "default" to be visible in add-on form and to support upgrade steps in add-on form.