Create a users directory

[ivanminutillo]

Related to #215 #217

• Create a specific route that list all the users that belong to the instance
• Make the user list visible to guests/users/admins, based on a setting in instance config
• Filter user list based on boundary
• Instance-level default discoverability setting controls user being filtered
• User-level changing of the discoverability setting edits their user profile boundary

[jjl]

Because of how things are split up at the moment, it will need to go into bonfire_social (even though it's more of a bonfire_me thing).

it should filter for local users who are public (who you may :see, :read). the MVP would just be listing ordered by id (i.e. creation date)

[jjl]

i would also like to get in here now and add that this is not a feature many instances would want to have at all and it should be easily disabled.

[KarenKonou]

Even if an instance has the feature enabled, there should still be an option for users to opt-out individually (mastodon does this for example)

[edumerco]

Create a specific route that list all the users that belong to the instance.

Good, it should be linked from the admin panel, at least.

The route is visible to guest and it will be linked from the homepage

I'm not sure exactly why, but in that case, can a person opt out from the public directory?