Local User Notes / Tagging

[Sjmarf]

Allow writing locally stored notes on users, kinda like you can do on Discord. Also allow adding tags to users that are shown next to the name in the feed. Users should be able to set a tag color and short label. There should be a page somewhere to view all tagged users, or users with certain tags. You should be able to export tags to a file.

RES had this. Voyager and Thunder have this.

Relies on #1133

https://lemmy.ml/post/19667291/13476269 https://lemmy.ml/post/16412752/11428201