We have no way of detecting if a browser window is behind another window
or off screen on a virtual desktop.
In some cases we may want events to be delivered quicker to the browser.
Specifically a user may still have a window in view but is not interacting.
This gives users 20 minutes of extra "long polling time" prior to shifting
to short polling.
Previously we would consider a user "present" and "last seen" if the
browser window was visible.
This has many edge cases, you could be considered present and around for
days just by having a window open and no screensaver on.
Instead we now also check that you either clicked, transitioned around app
or scrolled the page in the last minute in combination with window
visibility
This will lead to more reliable notifications via email and reduce load of
message bus for cases where a user walks away from the terminal
