DABstar V2.2.0

AppImage of DABstar V2.2.0, based on Ubuntu 20.04, tested on Ubuntu 22.04.

What is new in 2.2.0

• A bigger fix replaying files regarding my new service list introduced in V2.0.0.
  There is still the small issue that the channel name does not (necessarily) fit to the file content.
• There is only one file-reading dialog now. The file type selection happens in the file dialog field.
  It is selectable whether the QT or native file dialog should be shown.
• Improve error checking for file handling.
• Refine the setting management.
  This causes that the setting file (in ~/.config/dabstar/) got a new filename.
  So, the settings has to be put-in new.
  Same happens to the service-list database file, so possibly already made favorites got lost.
  Sorry for that circumstance.
• Small UI and many code refinements under the hood.

Full Changelog: V2.1.0...V2.2.0