enhancement: add idle timeout session indicator for inactive user

[tony-sn]

Hi Horizon-UI,

As an admin dashboard web application, it would be nice if we can apply a session timeout indicator for our admin / user. I am only talking about UI perspective, not about logging out the user / admin of the application with logic.

An illustration of this UI practice could be a blinking badge with "Inactive User" message like the one we have seen at Codecademy when the user is inactive.

Or it could be fancy as a loading spinner at user avatar, with a Tooltip shows "Inactive User" / "Session Timeout Countdown"

Thanks, Horizon-UI Team.

Tony