Implement the Power Manager

The ReactOS kernel drastically lacks in power management mechanisms, most of the code of it is non-existent. We do not implement power policies, battery information monitoring, thermal management and throttling and we do not support hibernation.

Since that subsystem is a stub in its entirety, it would make sense to write that piece of the kernel following the Windows 8.1 way, as power management framework (PoFx) was introduced starting with 8. This will allow the use of power management device drivers written with WDF for ReactOS.

https://learn.microsoft.com/en-us/windows-hardware/drivers/kernel/overview-of-the-power-management-framework
https://learn.microsoft.com/en-us/windows-hardware/drivers/samples/power-framework--pofx--driver-samples