Add more tests
Add more tests

The tests added here include checks for expected types in
the library (including enum types that are needed for
introspection), and for error handling around names.

Closes: #2245
Approved by: alexlarsson

flatpak/flatpak,matthiasclasen/flatpak,flatpak/flatpak,flatpak/flatpak,flatpak/flatpak,matthiasclasen/flatpak,matthiasclasen/flatpak,flatpak/flatpak,matthiasclasen/flatpak,matthiasclasen/flatpak