Make the confirmation more scary when reinstalling a USB stick that has a Persistent Storage

Right now, the experience when upgrading and reinstalling from Tails Installer is too similar:

vs.

We could instead:

• Remove the confirmation dialog when upgrading.

• Make the confirmation dialog more scary when reinstalling:

  • Without Persistent Storage on the target USB stick:

    **Confirm the target USB stick**
    
    ⚠
    
    15.5 GB TOSHIBA TransMemory device (/dev/sda1)
    
    All data on this USB stick will be lost.
    
    [Cancel] [Delete All Data and Install]

  • With a Persistent Storage on the target USB stick:

    **Confirm the target USB stick**
    
    ⚠
    
    15.5 GB TOSHIBA TransMemory device (/dev/sda1)
    
    The Persistent Storage on this USB stick will be lost.
    
    [Cancel] [Delete Persistent Storage and Reinstall]