Modernize tutorials for recent lilbhandy
The python tutorials at https://source.puri.sm/Librem5/example-apps are outdated since they still use Libhandy-0 instead of libhandy-1,see e.g. https://source.puri.sm/Librem5/example-apps/adaptive-ui-title-bar/-/blob/master/src/main.py#L12 - several patterns changed so it would be great to have them updated.
handy-1-demo app can be used as a reference for common patterns.
(it might also make sense to move the demos to gnome.org at some point later on since they could help there as well)