Additionally, allow it to both check whether a room is currently apart of the public directory, as well as
publish and remove rooms from the public directory.

Generalise public rooms check, allow blocking removal from public rooms dir as well.

Remove the check on alias association, that is unrelated.

Note that we now execute the same behaviour as when publishing the room is
blocked by the homeserver config. That is, we now 403 the /createRoom call
instead of just letting the room be created without entering it into the public
rooms directory.

Finally, only call check_visibility_can_be_modified if it exists.

Additionally correct all mentions of a 'Public Room(s) Directory' -> 'Public Room List'.

….rst

Suggested in matrix-org/synapse-dinsic#63

…rd_party_event_rules_public_rooms

…rd_party_event_rules_public_rooms

* 'develop' of github.com:matrix-org/synapse: (109 commits)
  Add logging on startup/shutdown (#8448)
  Speed up unit tests when using PostgreSQL (#8450)
  Allow background tasks to be run on a separate worker. (#8369)
  move #8444 to 'feature'
  linkify changelog
  1.21.0rc2
  1.21.0rc2
  Fix bug in remote thumbnail search (#8438)
  Include a public_baseurl in configs generated by the demo script. (#8443)
  Fix DB query on startup for negative streams. (#8447)
  Convert additional templates to Jinja (#8444)
  Fix malformed log line in new federation "catch up" logic (#8442)
  Add unit test for event persister sharding (#8433)
  Add config option for always using "userinfo endpoint" for OIDC  (#7658)
  Do not expose the experimental appservice login flow to clients. (#8440)
  update changelog
  fix a logging error in thumbnailer (#8435)
  changelog fixes
  fix version number
  1.21.0
  ...