deploy: move the queue toggle

Same shape as the others. Three of the eight references were prose
rather than code: two assertion messages naming the option to an
operator, and a `defaultText` in the authelia module, whose
`oidc.hiveIdentities` derives from whether the queue runs here.

Also corrects a comment in swarm.nix that this commit's own hunk sits
directly beneath. It said `enableRequiredServices` turns on matrix and
authelia "but NOT nats (nats has no mode that enables it)", which stopped
being true when the queue was added to that switch — before this change,
not by it. The reasoning it introduces is still right and still worth
keeping; only the premise had expired.

nix/host-modules/swarm-controller.nix

@@ -539,7 +539,7 @@ in
           services.hyperhive.swarm.controller.queue.natsUrl is unset.
 
           It defaults to loopback only when this host also runs the queue
-          (`services.hyperhive.swarm.nats.enable`). A controller on its
+          (`services.hyperhive.deploy.nats`). A controller on its
           own host has to be told where the queue is.
         '';
       }