CLI Style Conversion Doesn't Copy <musicalSymbolFont> to Parts

Minor as the CLI is probably not used by many users.

Hi,

When using the CLI interface to apply styles, the Musical Symbol Font does not propagate to different parts, and applies only to the score.

In particular, upon examining the MSCX, the node MuseJazz is applied only to the score, and not the parts.

To reproduce this, one can run the following command to attempt to apply the MuseJazz musical symbol font. The resulting output file, "JazzedUp.mscz" will contain parts that do not have any defined at all whatsoever, but the score will have the proper style applied.

[musescore location] NotJazzedUp.mscz -S style-with-musejazz.mss -o JazzedUp.mscz

To make this more complicated, it appears that there is different default behavior between MuseScore 3.0.5 and the current latest nightly build (tested with 3.1.0), when is not specified. MuseScore 3.0.5 appears to use the font defined for the score for the individual parts, while MuseScore 3.1.0 defaults to one of the other fonts. This can be observed in the files MS3 vs Nightly PNG files, and reproduced by opening up the output file (JazzedUp.mscz) in MS3 release vs nightly.