Greeter revamp: refine design according to expert feedback

Building up on https://labs.riseup.net/code/issues/8235#note-11 we should refine our current design to fix those issues. See subtasks.

Attachments

• 
• Greeter.States.svgz
• 
• Greeter.Explained.svgz
• 
• Encrypted.Storage.svgz
• 
• 
• Greeter.Privacy.svgz

Parent Task: #8230 (closed)

Subtasks

• #8968 (closed)
• #8974 (closed)
• #8976 (closed)

Related issues

• Blocked by #8235 (closed)
• Blocked by #8233 (closed)
• Blocks #7550 (closed)

Original created by @sajolida on 8967 (Redmine)