Reintroduce "Set End Time" or Duration in Annotation Item

That was Jean's proposal back then. Since we are displaying the duration, I would propose to call it "+ Add Duration". Not sure how this could be implemented but it would be great if users can choose between 1) setting a duration in the format hh:mm:ss.sss OR 2) setting an end time by selecting a moment in the video after the start date of the annotation (in the video player or swimlane).

@milan.gress: since you have been adjusting the chips in the annotation item, could you take a look at this?