Function lemmy_apub::activities::comment::collect_non_local_mentions

pub async fn collect_non_local_mentions(
    comment: &Comment, 
    community: &Community, 
    context: &LemmyContext
) -> Result<MentionsAndAddresses, LemmyError>

This takes a comment, and builds a list of to_addresses, inboxes, and mention tags, so they know where to be sent to. Addresses are the persons / addresses that go in the cc field.