Enable links to specific comments in a discussion

In the old PI Square, there were direct links to each post in discussion thread, which was handy for (at least) the following three use cases: 1. Alerts (email or on the site) for new posts on a discussion took you directly to the new post. 2. Alerts (email or on the site) that you were @mentioned in a post took you directly to that post. 3. Ability to reference a particular post that contains the information of interest (e.g., sending a link to customer or coworker to help with a particular issue). The three use cases above are particularly annoying for longer discussions since the best we can do is link to the discussion, which brings users to the first post and leaves them needing to scroll through all posts to find the one of interest.