Tooltip : animate transform on leave

[Ericlm]

Hello there! I don't find a way to have an animation triggered when a TooltipContent is being leaved. It works perfectly with the example, when the content is shown; however, I don't know how to do that when the content is hidden.

I also tried to use the Transition component from Vue, but while it works for things like opacity, it doesn't seem to work with anything that is related to transform. (so scaling down doesn't work).

See #712