[Secure backup] Last session logout without recovery

[stefanceriu]

From element-x-ios created by stefanceriu: element-hq/element-x-ios#1903

When attempting to sign out from their last session the user should be prompted to setup recovery so they don't lose access to their encrypted messages

Design

https://www.figma.com/file/0MMNu7cTOzLOlWb7ctTkv3/Element-X?type=design&node-id=12495-22145&mode=design&t=lxXaFMJStZVxqef3-0