`Label` control implementation of tooltips is unintuitive with `MouseFilter`

[mqole]

title. assign a label a ToolTip in a ui, hover over it, and the text doesnt show.

investigating shows this is because for the ToolTip to show MouseFilter needs to be set off its default value of Ignore. this is pretty unintuitive behaviour, and should either be documented or handled somehow (should supplying a label with a ToolTip automatically change the value of MouseFilter?