Mark posts where the sender can not see your interactions with it

**Is your feature request related to a problem? Please describe.**
There are two types of posts where the sender are not actually in the fediverse in any meaningful way, and can not actually see your likes, boosts or replies: Posts from bird.makeup and other Twitter clone instances, and posts from Threads.

It would be very useful to be able to be aware in a glance if a post you see is one of these types of posts, because it might feel like a waste of time to interact with them, or maybe you don't want to boost posts like that, or for any other reason.

**Describe the solution you'd like**
In the same way that boosts and posts from followed hashtags are marked with a special icon and background color, these posts could also have the same.

**Describe alternatives you've considered**
I don't know, really. Anyone could of course just choose to block these servers, but I feel like it can be valuable to be able to see them, but still easily know what they are. Just a suggestion :)

Thanks!