Add general "Prevent sleep" option to the Tools menu and provide a keyboard shortcut for it

[x-magic]

Related to: #3682 #3813

Only noticed such feature in BD today. I'm currently using Amphetamine to prevent Mac from falling sleep (only indefinitely) when needed.

It would be great if the "Prevent sleep while connected" is not hidden in "manage display" submenu but rather can be pulled to the top level menu, or a button or sort can be added to the monitor tab bar. Of course keyboard shortcut would work, too, but maybe tricky since this is a per-display setting?

(I really meant to attach the button to MacBook's built-in display so it can be used without external monitor connected)

[waydabber]

Maybe I should just add a general option to prevent sleep as well. The idea for this feature originally was to automatically prevent sleep when a display is connected (ideal for TVs or Projectors typically used for presentations), not to be an Amphetamine replacement.

Added an issue about it:

#3935