Fix #20907 - Regardless of check code in a plugin, starting a plugin with no score open crashes the program.

A diagnostic "prinf" statement was unconditionally trying to access the score name, even with no score. Corrected by adding a condition.
Merge pull request #329 from mgavioli/Fix_20907_plugin_no-score_crash

Fix #20907 - Crash when starting a plugin with no score open
Merge pull request #328 from lvinken/20581-capx-impl-3

20581 capx impl 3
Fix #20905: Can't nudge frames with keyboard

ScoreView::editKey() passed to Box::editDrag() bogus hRaster and vRaster values in the EditData struct.
Merge pull request #330 from mgavioli/Fix_20905_no_keybrd_nudge_for_frames

Fix #20905: Can't nudge frames with keyboard
Fix #20782 - Adding or removing a section break (with a "Restart from meas. 1" default) does not immediately renumber measures.

Added calls to Score::renumberMeasures to relevant cases of MeasureBase::add() and MeasureBase::remove(). This also ensures that measures are renumbered when the property of the section break is changed.
Merge pull request #331 from mgavioli/Fix_20782_Section_break_does_not_renumber_measures

Fix #20782 - Section break and measure renumbering
change default size of piano
fix #20987: Text style of header is not applied
more buildin note groups
fix performance regression for layout
fix #20989: Crash if exporting empty score
fix #20912