Allow seeing all users who reacted to a message

[davidb]

This has been added now, see more details here:

New Reactions Popup in Chat

We’re introducing a new reactions popup in chat to make it easy to see all users who have reacted to a chat message. When hovering a reaction on desktop you will see a list of users for that specific reaction: [Hovering a reaction on desktop] When there are multiple different reactions for a post — a menu appears to filter by type: [chat-reactions-popup] On mobile you can see the reaction user list by long pressing the reaction. How to enable the new chat reactions popup For now, …