🚀 [Feature] Mute groups

[sushidave]

🚀 Feature

As a user, I want to mute individual groups so that their posts don't appear on my newsfeed.

Tasks

1. Add an mute/unmute function on the group overview page.
2. Add provisions in the database and database queries.
3. Add a user settings page with a list of muted groups and a function to unmute them individually.
4. Filter out affected posts to display on the newsfeed page.

As discussed with @Tirokk.