Allow multi-dimensional rating of issue comments

Problem:
Often when I follow an issue in the Drupal issue queue, I find post by people (sometimes myself) who obviously didn't read all posts. Even worse: Some issues require a read-up of a bunch of related discussions before you can do any reasonable participation. I can't blame anyone for that - time is money! The consequence is that arguments have to be repeated again and again, and discussions go around in circles. We are wasting a lot of time. Time of otherwise expensive experts. And finally, we get suboptimal solutions, because the decision makers have the same problem.

This is why I would appreciate a voting or rating system for issue comments.
I say rating of comments, not rating of issues, because the biggest signal to noise problems are in the comments.
The voting should be multi-dimensional, because usually a reader wants to find the best comments for one specific purpose (summary, patch etc), not just the best comment in general.

Voting Dimensions:
- Original / new contribution, good idea, good research etc. The purpose is to reward the author and give proper attribution. A comment or patch with this rating is maybe not the best one, but the first who came up with a new approach.
- Recommended summary. A summary can repeat a lot from previous comments. It doesn't need to be new or original, but it should allow the reader to skip other posts.
- Recommended patch.
- Important use case / requirement.
- Important argument.
- Excellent proposal / algorithm / concept to solve the problem.
- I support this argument / opinion. This dimension can pull the opinion stuff away from the other dimensions.

Purpose:
- Allow to quickly get an idea of an issue, by reading only the comments highlighted as "summary", and skipping irrelevant or outdated issue comments. This can even mean to skip the starting post, as it often contains unfinished ideas that have been refined in the comments.
- Encourage summary comments which give a complete overview.
- Allow to quickly find recommended patches.
- Reward quality contributions, and show them on the user page.
- Reduce the time wasted on writing the same argument twice or more, only because some people didn't read all comments.

the purpose is NOT to have a rating for each and every single comment, but to highlight those comments that stick out and are worth reading.

Possible technical solutions:
- A new module based on Voting API, similar to Fivestar but multi-dimensional. There have been arguments against Fivestar in the issue voting feature request (see below), maybe the same applies here. It was said that drupal.org shouldn't depend on the Voting API module. And Fivestar in its current form does not allow multiple dimensions.
- Something new and custom only for drupal.org.

Conceptual problems:
Separate trails of solution: We often have the situation that we have 2 or more different approaches to the same problem, each with a series of comments and patches. Usually you want to find the latest and best of each, and compare them. A simple voting system would not help with this, no matter how many dimensions.
New comments supersede old ones: An old comment might still have the best rating, but there might be a newer comment that contains the same information and more.

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Related issues
#42232: Help Maintainers Manage Issue Priority by Encouraging Voting -> the same for issues themselves. Please note that the purpose of this is very different.
#682178: Drupal Strategy Wiki to sort+summarize information from the issue queue. -> this would be an alternative, but it would pull activity away from the issue itself, and not necessarily be helpful.