Whether the application is connected to the server or not.
Every periodic network polling should be paused while this is set
to false. Extensions should use this value to decide whether to proceed
with the polling.
The extensions may also set this value to false if there is no need to
fetch anything from the server backend basing on some conditions
(e.g. when an error message dialog is displayed).
At the same time, the extensions are responsible for setting this value
back to true.
Application connection status