Add emote reaction notifications in text channels / dm

Some people like me not really like to send primitive responses such as “OK/Good/Fine/Yes/No” to the final messages, but it's hard for your interlocutor or you to know about such reaction until you check the message again. Because of this, you can miss an important notification. For example, I use Discord to communicate with my colleagues, and in order to avoid flooding in conversations, we use reactions (for example, instead of reply to a message with "“OK/Good/Fine/Yes/No”, we simply respond with a reaction to the message 👍 /👎) Notification like this allow to know you had seen the message and reacted to it or that your message has been read