Add a Visibility Settings to posts (as in Twitter Circles)

[GustavoAlvess]

Is your feature request related to a problem? Please describe.

A neat feature that Twitter had was Circles, where we could create a post that only a restricted group of people could see, without having to resort to separate private accounts, which was very convenient.
Bluesky currently does not have an equivalent feature, and I believe I didn't see any github issue relating to that.

Describe the solution you'd like

Bluesky already has Quote Settings and Reply Settings, so Visibility Settings could fit very well. Ideally, being able to create more than one group would be great (i.e. "irl friends" and "followers who like video games"). Some existing presets could also help, like "followed users", which Reply Settings already has.

This could all go in the Post Interaction Settings menu, since it fits the concept like a glove.

Describe alternatives you've considered

Just being able to create and customize a single "circle" would be nice already, and hopefully not as demanding on the team.