Dim or switch lights off when computer is locked

[Pander]

Please describe the problem would like to solve
when a computer is locked, keyboard lights and screen go off, to save power and not to be disturbing.

Describe the solution you'd like
Add a setting to dim the lights in the device or switch them off completely when computer is locked.

This will depend on the existing issues and PR for not allowing input from the device when a computer is locked.