Address Circularity of externalSelection Watcher in ScoreSetHistogram #608
Description
In order for the histogram to remain responsive to datum selections from parent components, it has a watcher on the externalSelection prop that propagates changes to the histogram. However, certain histogram actions also have the ability to change the externalSelection property which then causes the watcher to fire unnecessarily (We'd like to be responsive to changes from parent components, but don't need to respond to changes from the histogram child).
One possible option could be some sort of refactor to use a computed property or a method, hopefully eliminating the reactivity between the parent and child on the shared watcher prop.