introduced `notificationTexts` function to reaction message spec. Keeping the notification text generic for now with "user liked a message" and "user unlike a message", but will put up a follow up task to further improve the notification text because what I mention below is a bit out of the scope for the first version of message liking
# Only send a notification if the user adds a like/reaction
# Rescind a reaction notif and don't show anything new if the user removes a like/reaction
# only the user who sent the target message gets a notification
---
Depends on D5854 and D5690
Linear Task: [[ https://linear.app/comm/issue/ENG-2245/setup-message-reaction-spec | ENG-2245 ]]