Pass event instance to the listeners

[stockiNail]

Currently the listeners on the labels are receiving only the context.

I think it could be helpful to get also the event instance, separately, as additional argument.

A use case where to use the event could be to check if any modifier key is pressed in order to perform own logic only when a key is pressed.

Type:

type Listener = (context: Context, event: ChartEvent) => boolean | void;