Auto destroy Vue component zombies in Karma
Description
This MR adds a Vue plugin which tracks and gracefully destroys all mounted Vue roots (in order to prevent zombie components from effecting outside specs)
Context
Original title and description
# Add Vue $destroy verification to karma suite
## What does this MR do?
This MR adds a verification that every call to `Vue.prototype.$mount` has a matching call to `Vue.prototype.$destroy`.
It's concerning how many violations there are to this :grimacing:
Edited by Paul Slaughter