Bumps k-ap to 0.3.1 which adds bio, banner_url, followers_url,
following_url, and also_known_as to RemoteActor. These are populated
from fetched actor JSON at follow/ingest time so followers and following
listings no longer return null profile fields.
Adds migration 015 for the new remote_actors columns, updates all JOIN
queries in postgres-federation to select and return the new fields, and
maps them through k_ap_actor_to_domain.
Also fixes clippy: remove empty line after doc comment in port.rs.
