[MusicXML export] Lyrics do not handle flat and sharp signs
Found this in 1.2, verified it with my own build of the sources from a few days back; I have no reason to expect it's been fixed since then.
Steps to reproduce:
1. Open attached score (created in 1.2)
2. Note the use of flat and sharp signs in the lyrics - these were added through the text symbol palette
3. Export to MusicXML
4. Open the resulting MusicXML file
Expected result: lyrics appear as before, with flat and sharp signs
Actual result: garbage characters are present in the MusicXML file
I am not sure if there is any sort of standard escape sequence that could be used here - that is, I don't fully expect other programs would recognize the symbols. But I'd hope at least MuseScore could recognize its own symbols.