Issue: A guest streamer is on host streamer's channel without going live themselves, there is no way for guest's community to know about this collaboration.

Individuals that have notification on for guest are very much interested in going to host channel if it means they get to see their streamer and community member. Often to navigate this issue , guest go live themselves and screenshare the host stream. This is a hassle to set up and waste of resources to do essentially a rerun, leading to a lot of streamers to just not bother with it.

This is a big loss in potential viewer retention, and loss on possibility of viewers getting more involved in other twitch community. This also allows streamers to easily collaborate without much setup.

Solution: A guest appearance ping should be added by default on the "all" notification. Disabling is possible in advance settings.

When a guest appearance is going on, the host stream should appear on the follow channel tab/side bar as if the guest streamer went live.

For streamer to be a guest appearance, they would need to
- not be streaming themselves
- have login to their and host's account, where they can verify the guest appearance by either qr code or something.