Add demo_printer again (port from v7 to v8)

In lvgl_demos /lvgl_examples, there was a very nice example project call demo_printer. It got lost or was not partet to v8 and thus it was removed.
Since it was one of the best examples (beside the music player), it would be very nice and helpful, if it would be adjusted/updated to lvgl v8 and added back again.
I have tried to port it, but got lost after some time (not good enough in lvgl and V8 at all).