[WIP] Add event bubbling support to InfoboxManagerView

Unit tests:

1. This test verifies that mouseenter and mouseleave events on a specified child of the container triggers managing of infoboxes, whereas the same events on unspecified children do not.

2. This test verifies that mouseenter and mouseleave events on all specified children of the container, when multiple children are specified, trigger the managing of infoboxes.
HELP:

Both tests are currently failing when spying on _onTargetMouseEnter. Additonally, although the spy is saying that _onContainerSelectorMouseEnter and _onMouseLeave have been called, I do not see the console logs I added to these methods. I am unsure as to what is happening, any help would be appreciated!