Suggested amendments for PR 7918

[AlexHentschel]

This PR has documentation revisions only, which I would suggest to include in #7918.

If you can spare the time, it would be great if you could take a detailed look at the VoteCollector, specifically:

• This proof showing that we never miss votes (essentially a liveness proof). You didn't change anything in this regard and the code seemed plausibly correct. However, it took me some time to refresh my memory and convince myself that it is in fact correct. Therefore, I thought it would be good to document the liveness argument more formally inside the code.
• This documentation explains how we distribute the responsibility of detecting equivocation attacks and double-counting attacks.

Please take a critical look, whether my suggested documentation revisions (especially the proof and explaining the responsibility of detecting equivocation) are clear and can be followed.