Do not auto-auth bare domains

Bare-domain JIDs match the "transport" condition, and were getting
auto-authorized.  Not only is this a privacy problem (anyone with a
bare-domain JID can get your presence) but it's also a usability problem
(since the GUI does not allow initiating a subscription request the
other direction).

If a UI flow wants a JID auto-authed it can add that JID to
self.jids_for_auto_auth and this code will still fire.

Closes #8597
Status Job ID Name Coverage
  Test
passed #1612
run-test

00:00:23

failed #1548
run-test

failed #1546
run-test

 
  Build
passed #1547
run-build

00:00:13