chore: update vexflow to 1.2.87
chore: update vexflow to 1.2.87

adds directionless arpeggio, removes npm audit vulnerabilities from vexflow
change percussion note head, add square, rectangle note heads
see vexflow issue #660 for changelog

opensheetmusicdisplay/opensheetmusicdisplay,opensheetmusicdisplay/opensheetmusicdisplay,opensheetmusicdisplay/opensheetmusicdisplay