The watchdog was used in a few places as a shortcut to skip reading
data. Further, it was used in some places in the UI to display
connectivity. But it also introduced quite some complexity. In some
cases it can be fragile: network accessibilty cannot be looked up on all
platforms/hardware constellations. The connectivity could change
between the last watchdog call and the real call. Hence all readers must
still handle the case where the connection fails.
To simplify swift and further reduce the dependency onto the project
infrastructure (pings etc.), this removes the watchdog.
This also removes the QNetworkConfigurationManager, which is deprecated
and not available with Qt6.
Previously we already switch to loading the bootstrap file only from the
local file (ec42553910).
This removes the remaining parts of loading the bootstrap file from a
remote location.
This also updates the UI in case of parsing errors of the bootstrap.json.
This is an intermediate step to have smaller unit tests. It is a trade off
between having many many test executables compared to a few bigger ones. But
this comes a lot closer to what QtTest is meant to be used.
