Enables pasting FiguredBass elements.

To be sure the element is pasted into the right track, the track is set again after reading the element.
This also affects Dynamic, Symbol, FretDiagram, Marker, Jump, Image, Text, StaffText, TempoText.
more inspector changes to convert to new scheme
fix changing note head color
more inspector cleanups; add measure property Measure Number Mode to allow adding/removing measure numbers on top of style rules
fix #17941 expose stem width in style editor
fix #20355 Undo causes crash when undoing a note smaller than quarter note
fix #20352 implement measure numbers for all staves
enable initialization of concert & transposing clef from instruments.xml
Merge pull request #236 from mgavioli/Figured_bass_enable_copy

FiguredBass: Enables pasting FiguredBass elements.