Cacher client installation state included in the common update state as
all qubes that updates with Qusal states use it, rather than including
it on all the installation states. The macro utils.macros.install-repo
still also run's apt-cacher-ng-repo in case the user is not updating at
that moment, just adding a new repository without restarting the qube
(systemd service has already ran).
Fixes: https://github.com/ben-grande/qusal/issues/66
Updates happens multiple times, normally 2 to 3, even if we consider a
state without includes. On states with multiple includes, it could
easily get approximately 10 updates being ran. This behavior leads to
unnecessary network bandwidth being spent and more time to run the
installation state. When the connection is slow and not using the
cacher, such as torified connections on Whonix, the installation can
occurs much faster.
Adding external repositories has to be done prior to update to ensure it
is also fetched.
Fixes: https://github.com/ben-grande/qusal/issues/29
