fix #3325: layout of multi-voice seconds and unisons
fixes, tweaks, and optimizations
handle dots
fix double dot and one case with single dot
fix #22463: correct accidental placement for offset chords
optimizations and debug statements
correct determination of stem width
improve accidental positioning
fix sharp overlap/undercut
tighter spacing between sharp & natural
switch to zig-zag accidental stacking order
fix accidental position with multiple seconds
fix for accidental position on first ledger line
add vtests
make sure floating point round doesn't interfere with detection of accidental conflict
improve font independence of accidental layout
update & add tests
enforce accidental distance even for overlap
Selecting [undefined] TPC in Ambitus inspector causes crash.

The [undefined] item is informational only (when the ambitus range cannot be calculated, for instance when there are no notes in the staff yet) and should not be selected.

Fixed at two levels:

1) The [undefined] item is disabled and cannot be selected any longer

2) The Ambitus::layout() method is more robust to in dealing with undefined ranges.
Merge pull request #770 from MarcSabatella/3325-seconds

fix #3325: layout of seconds and other conflicts in chords