PERF: Async notify users after inviting group (PR #12697)

Inviting a group generates a notification for each member. If this happens synchronously it may take a while, leading to a poor user experience.


if post is nil this will blow up :boom:

I like to exit early like this

      return unless user = User.find_by(id: args[:user_id])
      return unless group = Group.find_by(id: args[:group_id])
      return unless post = Post.find_by(id: args[:post_id])
      return unless topic = post.topic

Do you need to create a new PostAlerter instance for every group member?

This bit could also be generated once outside the loop.

Yay :raised_hands: Async + moar perf :tada: