win32: enso hotkeys not working if uac is enabled and administrative process is on top

[tartakynov]

Enso hotkeys not works if an administrative process is on top since administrative processes are isolated from non-administrative processes running on the same user desktop and these processes hooks all windows events without passing it to Enso.

One of obvious workarounds is to use some administrative code running in background as an input manager so it can interact with administrative processes