Failover for lizard

Originally created by @intrigeri on #6185 (Redmine)

Team: bertagaz, intrigeri

Blueprint: https://tails.boum.org/blueprint/lizard_failover/

Subtasks

• #6186 (closed)
• tails#6190 (closed)
• tails#6191 (closed)
• tails#6249 (closed)
• #6250 (closed)
• #10243 (closed)
• #10244 (closed)