setPeer(instance: string,status: PeerStatus): Promise<FederationPeer>
Puts the instance instance names, by its API's address or its pages'
(resolveIssuer), on the list of status, for /manage, and returns it. A trusted one must answer as a gerbeur instance, whose name
is kept; a blocked one is blocked whether it answers or not, keeping the
name it had. Blocking one ends the sessions of its users here at once:
their tokens stop counting by getSessionState, and this closes their
sockets.
status: PeerStatus
Promise<FederationPeer>