Expand all discussions button in MR
Description
When trying to read a MR with many resolved discussions, it's very hard to find a certain discussion, since all threads are collapsed.
For example, when I remember a certain topic or issue has been discussed within the MR, I cannot use the browser search on the discussions view. Instead I have to go through all discussions and click on each "toggle" button until finding the right one. This is very annoying since it happens to have 30 and more discussions in one MR.
Proposal
Provide a "expand all" discussions button on the top of the discussion list. E.g. left to the "x of n discussions resolved" button.