This adds a new component that manages Plasma Mobile specific configuration on every session startup. It also restores configuration when logged into a desktop session.
This allows us to remove https://invent.kde.org/plasma-mobile/plasma-phone-settings, as well as configuration that was set in the look and feel. This also gives us an easy way to control configuration upgrade paths, and in the future, add ways for the configuration to easily be reset for debugging purposes.
When disabling mobile data, instead of setting the autoconnect flag to
true for the current active connection, set it to false for all
connections without exception. When reenabling mobile data, instead of
looking for a connection with autoconnect set, look for the connection
with the latest last use timestamp, set that one to autoconnect, and
also connect it immediately.
There should not be any connection with autoconnect enabled if mobile
data is disabled, because that makes NetworkManager reconnect it after a
reboot or a modem restart. The autoconnect state on the modem is
apparently lost on reboot.
Also change the SignalIndicator::mobileDataEnabled() getter to account
for the above.
Fixes#182.
