[Feature Request]: Special case in Screen::handleSetOff() for E-Ink displays

[todd-herbert]

Platform

ESP32

Description

After several minutes at idle, log gets message [PowerFSM] Turning off screen.
After this point, the E-Ink display does not receive any updates until user presses a button to wake the device.

Because the E-Ink display image persists, even after Screen::handleSetOff() runs, it is not immediately clear that display updates have suspended.

It may be worth considering either:

• Allowing the E-Ink display to remain active
  Unlike traditional displays, there is no considerable standby power consumption.

• Moving to a standby screen before "turning off screen"
  This would make it clear to the user that updates are suspended, and that a button press is required to display current info.

[thebentern]

Will be closed by #3477