feat(carousel): Use transitionend event instead of setTimeout
feat(carousel): Use transitionend event instead of setTimeout

setTimeout for timing transitions can be iffy at best (especially when view port is obscured)

This fix removes the setTimeout and replaces it with a "once" `transitionend` event
bootstrap-vue/bootstrap-vue,sschadwick/bootstrap-vue,tmorehouse/bootstrap-vue,bootstrap-vue/bootstrap-vue,sschadwick/bootstrap-vue,sschadwick/bootstrap-vue,tmorehouse/bootstrap-vue