Broadcast round widget selector to have header

[ijm8710]

When viewing a broadcast with a lot of rounds and scrolling up to choose round 1, 99% of time the fast scroll causes the widget to just close instead of selecting the top row (round 1)

I think this could be improved by adding "7 Rounds" (or whatever #) at the top as a header.
This also adds consistency as the chapter widget for studies has a header (see the study chapter selector 1st photo below for reference).

• Add header to
  Broadcast round selector
• For more consistency,
  Should probably do the same for the divisions selector widget as well
• thirdly, often I'll run into this weird edge case where when I do want to dismiss the widget, it gets stuck midway (see 2nd photo). I am not sure why but I know other apps that use these type of selectors, usually don't have this issue so I think it can be avoided.