[Feature] StopWatch class missing a way to tell if it's paused

[gyenesvi]

The StopWatch class offers a way to pause it, but does not offer a way to decide if an instance is paused. This seems to be a hole in the API, and could be useful to keep track of some state changes without introducing an extra variable for that (I am assuming that the paused state is actually stored somewhere inside). I'd propose adding a method called paused, returning a bool.