ui: toggle confirmation and dialog redesign

[incognitojam]

Show confirmation dialog for toggling experimental long:

• The param isn't written until the user confirms, and the toggle is switched back if they cancel
• Also updates the ConfirmationDialog style (no more white dialogs)

Other dialogs:

Dialog	New	Old
Training guide
Reset calibration
Reboot
SSH Key
Regulatory (no change)
Branch switcher (no change)