MusicXML page settings not saving.
See the two attached files. The .xml file was created by v2 MuseScore. The .musicxml file was created by v3 MuseScore.
The .xml file has a section near the top with page layout data, width, height, margins. That is completely missing from the .musicxml file.
I'm working on page settings in this module anyway, so I'll include it in my PR here: