Add End Time to AnnotationItem

Currently, the Annotations do not display the End Time of the annotation.

This is a confusing behaviour, especially with addition of time ranges in the new swimmlane: #899 (closed)

I see alternative solutions & formattings:

1. simply keep the hh:mm:ss.sss format with a divis:
   • 00:00:08.687 - 00:00:09.687
2. Use a relative timestamp:
   • 00:00:08.687 + 00:00:01.000
3. Use a relative Time String:
   • 00:00:08.687 1 Second
4. More explicit:
   • 00:00:08.687 duration: 1 Second

I would prefer Version 3 as it is the most readable and (looks) less technical. Even in the case, if someone does actually need the exact time, there would still be the possibility to click on the chip to go to the exact end time.

Although we would lose precision, → 00:01:15 would probably be turned into: 1 Minute