This fixes a case where the update checker keeps an old reference to the previous updated version, despite running a newer version.
It also removes some use of `Assembly.GetExecutingAssembly().GetName().Version` with the information from `UpdaterManager.SelfVersion.Version` as that should follow the update info.
This fixes#5698
This fixes#5252
Added the --auto-update option to the commandline to allow automatic updates.
Added a new Duplicati.Library.AutoUpdater.exe tool to work with updates, especially handy if the update breaks the install and for manual handling of updates.