Greeter revamp: Feedback to the user which options are going to be used

We initially thought about a “Check and go” screen at the end of the assistant, but from the feedback from experts (#8235 (closed)) we were said that we should have something visble to know wich options are default if the user does not configure anything.

This could be either:

• Icons always visible on the screen (see icons on top of sections in the accordion proposal by tchou)
• A Check and go screen for everybody

On the other hand, the idea of having sensible options by default is actually to hide this complexity for the people who don’t want to know about it.

Blueprint: https://tails.boum.org/blueprint/greeter_revamp_UI/design_rationale_phase1

Parent Task: #8967 (closed)

Original created by @sajolida on 8974 (Redmine)