feat(ChordSymbols): Chord symbols update their bounding box in the skyline. (#467)
feat(ChordSymbols): Chord symbols update their bounding box in the skyline. (#467)

closes #464
opensheetmusicdisplay/opensheetmusicdisplay,opensheetmusicdisplay/opensheetmusicdisplay,opensheetmusicdisplay/opensheetmusicdisplay