Allow users to see hidden communities

[Ategon]

Requirements

• [X] This is a feature request and not a bug report. Otherwise, please create a new bug report instead.
• [X] Please check to see if this request (or a similar one) already exists.
• [X] It's a single feature. Please don't request multiple features in one issue.

Describe the feature you'd like

Currently when a community is hidden, the only way to get to it is by a direct URL (if you arent an admin). Instead of only having that, there should be a setting when browsing the community list that when enabled shows hidden communities in addition to non hidden communities.

[Nothing4You]

If this is implemented, I'd argue that this should be configurable by admin settings.

If I hide a community I'm explicitly not looking to have it discoverable if you're not explicitly looking for it by name.

[Ategon]

Main problem I guess is hiding communities is used for two different things

I mainly use it for making things not show up in the feeds but am perfectly fine with people discovering it outside of that. e.g. the lemmit.online bot instances

Maybe having two types of hiding in the api makes sense