Unlink references in mscore font

Glyphs with references in .TTF font are rendered with errors under Windows. This patch replaces the clef+numbers glyphs (which were using references to the individual components) with actual outlines.

In addition, position of numbers on bass clef have been improved (better balanced above and below).
Fix #23508 : A custom style set as default style in Prefs. is not used

Fixed by loading the preferences before loading the custom style

Also makes sure the custom style is complete, by initializing it with the built-in defulat style before loading.
Merge pull request #549 from mgavioli/Unlink_refs_in_mscore_font

Unlink references in mscore font
Merge pull request #550 from mgavioli/Fix_23508_load_default_custom_style

Fix #23508 : A custom style set as default style in Prefs. is not used