Provide extended tabbar preview

[sgraband]

Feature Description:

As a user it would be nice to get more information about the tab that i am about to open. Currently when hovering over a tab in a horizontal tabbar (e.g. in the editor area) only the file path is displayed for navigatable widgets. It would be nice to render some additional information there and also style the feedback.

For a start the title and the caption of the widget could be rendered, similar to how it is done in Google Chrome. While the title would be duplicate information for the tab itself, this would really be beneficial if the tab is not wide enough anymore to display the (full) text due to #12328.

Since there are already advanced renderings of hover boxes on the left tabbar we could reuse the same mechanism.

To not break/remove the current behavior this feature should only be enabled with a setting.