Navigation widget "Add pages" tool-tip is incorrect

Navigation widget "Add pages" tool-tip is incorrect

On the sidebar navigation widget the title has a tool-tip saying "Navigate pages" . However, the tool-tip also pops up when hovering over the circle+ icon whose function is "Add page".

This makes it seem that the circle+ icon is for some additional navigation function (perhaps to expand nodes in the widget), but instead it opens a dialog to add pages, of course.

Fix: Add a tool-tip (title attribute) to the span that implements the circle+ button.

Issue: ZGW1013.