Greeter revamp: Rework scenarios for "Guided"

• We have nothing matching the default config (Spoofing: ON, Camouflage: OFF). That feels weird.
  • “Web cafe” doesn’t make it clear that you are using a public computer
  • Add a “Default” option on top
  • There is no way of configuring bridges with the assistant!
    * We should maybe add another screen for that
    * We could activate the firewall option by default?
  • Propose an offline mode

Parent Task: #8231 (closed)

Related issues

• Related to #7551 (closed)

Original created by @sajolida on 8240 (Redmine)