Return discoverable via REST API (fix #12507)

[trwnh]

I think this should fix it?

https://github.com/tootsuite/mastodon/blob/master/app/serializers/rest/credential_account_serializer.rb is another place that it could be returned instead, but I think in the long-term it is valuable to know whether an account is discoverable even if it is not your own account.

[Gargron]

Maybe this also resolves #7822?

[trwnh]

I would be fine if we said toot:discoverable was also intended as an indexing flag, yes

[ClearlyClaire]

As you said in your last comment on that PR, those seem to be different concerns…

[Gargron]

Discoverable is a better indicator though because it federates. The noindex setting is local-only so it would never be correct for remote accounts in the API. Its use case is also so narrow that it's not worth federating, while "discoverable" could be used for multiple things that stem from one desire to be discovered or to not be discovered.

[trwnh]

if you consider the profile directory as a sort of index, then opting out of indexing would imply opting out of the directory, and vice versa would be similar enough to the point that maybe two different properties aren't needed.