Idle Service: Use the Idle Notify Wayland API natively

[ldelossa]

This task serves to replace the usage of SwayIdle.

Way-Shell can start listening to [https://wayland.app/protocols/ext-idle-notify-v1](Idle Notify) protocol to understand when the current seat has become idle.

From there we can map into useful functions like dimming the screen and running external scripts/applications.

This is a depedency on implementing our own screen lock service, as it provides the events to trigger our lock.