Fix #35136 : Tremolo bar always on top staff + crash on delete

A) A tremolo bar is always displayed on the top staff, regardless of the staff is it applied to

corrected by adding the ON_STAFF flag to a new `TremoloBar` object

B) Deleting a tremolo bar crashes the programme

corrected by adding the relevant case to the `Segment::remove()` method
fix #33391: view jumps when pasting in continuous view
fix #36621: display middle C as C4
fix #36641: "Edit Style" dialog wider and higher than necessary
reduce palettes for basic workspace
add workspace functions to palettebox
fix #36736: Articulation symbols too small and shifted left in "Edit Style" dialog
Merge pull request #1380 from jpfleury/36736-articulation-symbols

fix #36736: Articulation symbols too small and shifted left
Merge pull request #1379 from jpfleury/36641-edit-style-dialog-size

fix #36641: "Edit Style" dialog wider and higher than necessary
fix #35176: ottava layout in various special situations
Merge pull request #1378 from MarcSabatella/36621-middle-c4

fix #36621: display middle C as C4
Merge pull request #1377 from MarcSabatella/33391-adjust-continuous

fix #33391: view jumps when pasting in continuous view
Merge pull request #1376 from MarcSabatella/35176-ottava-end

fix #35176: ottava layout in various special situations
Merge pull request #1374 from mgavioli/Fix_35136_tremolo_bar

Fix #35136 : Tremolo bar always on top staff + crash on delete
fix #36746, link to handbook 2.0
remove unused stack-down action. Added here but never implemented http://sourceforge.net/p/mscore/code/4066/