[APIView UI] Must display some kind of indicator when a comment is unresolved but no longer visible because the line ID changed

Example:
- You see a name `badName` and leave a comment recommending `goodName`.
- Service team fixes badName and uploads a new revision.
- Now you see only `goodName` but because name name was part of the line ID, the thread where you commented on `badName` is still open but not visible. You can only get to it from the conversations panel (which basically no one uses and is confusing anyhow).

What we need is a way to show on the current APIView that there is a comment still open on a deleted lineId. You should be able to click that indicator to show the "old" line (i.e. in red like a diff view) and the thread. Or arguably since the thread is open the relevant diff should *just appear*. See https://github.com/Azure/azure-sdk-tools/issues/8420.