System still sleeps during say all

[LeonarddeR]

Steps to reproduce:

In Notepad++, initiate a say all when on battery

Actual behavior:

Observe that a system can still go to sleep or the screen can still lock

Expected behavior:

The system should not sleep or lock during say all.

Additional context

In #11118, the winKernel.ES_DISPLAY_REQUIRED flag was removed from SetThreadExecutionState

Proposed fix

Re-enable winKernel.ES_DISPLAY_REQUIRED, but make it opt out using a config flag.