Improve default filename for parts when using ...

saveAs or exportFile, using the same method as in exportParts.
Also set window title accordingly.
#33546: export key-accidental
#33546: move convertAccidental() to musicxmlsupport.cpp
#33546: import microtonal accidentals in non traditional key signatures
scale palette, selection filter, and inspector with -x option
update jazz templates
Merge pull request #1570 from MarcSabatella/scale-panes

scale palette, selection filter, and inspector with -x option
fix typo toogle -> toggle
Merge pull request #1568 from Jojo-Schmitz/part-filename

Improve default filename for parts when using ...
possibility to close startcenter from webview, open mscz from start center
Merge pull request #1569 from lvinken/33546-non-standard-keysig-musicxml

33546 non standard keysig musicxml
fix #39811: crash after removing multimeasure rests and adding a measure
Merge pull request #1571 from MarcSabatella/jazz-templates-beta-2

update jazz templates
smaller plus in startcenter
fix #41991: revert 21aebdc8ce
fix 41176: Crash when repeating a tuplet which value exceeds the time remaining in the measure
fix #41696: Barline added in a score does not appear in the parts and leads to a crash
fix new score wizard for empty template
new wizard fix: second try
confused with 00-Blank vs. 00-Empty