Enable special case handling in QubesOS

[daringer]

To allow proper deployment of the App2 and updates of NK3 devices inside QubesOS.

This should be a multi step approach:

• detect if app2 is run inside QubesOS
• allow to switch device into bootloader
• inform user that they have to re-attach the device in QubesOS (twice)
• tell the user to restart the nitrokey-app2
• show bootloader device and allow update