social.colibri.beta.community.applyLabel

Applies a label to a record in one of the community's spaces. This is how content is hidden, marked as a spoiler, or has its link previews suppressed. The record itself is untouched, since it lives in its author's own repo, but a `hidden` label stops this AppView serving the record: it is withheld from reads and from the events socket, and replies to it see a deletedMessageView in its place. Moderators holding `label.apply` and the record's own author still see it.