Fix wrong handler being used in SAML handler

See merge request new-vector/synapse!5

Factor out complete_sso_login and expose it to the Module API

See merge request new-vector/synapse!4

Add a whitelist for the SSO confirmation step.

See merge request new-vector/synapse!3

Add a confirmation step to the SSO login flow

See merge request new-vector/synapse!2

Fix #6910

Properly convert a coroutine into a Deferred in federation_base to fix an error when joining a room.

Some small fixes to the copy in #6907.

Make room alias lists peekable

Clean up and update federation docs

it's not in the spec yet, so needs to be unstable. Also add a feature flag for it. Also add a test for admin users.

we have hundreds of path_regexes (see #5118), so let's not convert the same
bytes to str for each of them.

* Increase DB/CPU perf of `_is_server_still_joined` check.

For rooms with large amount of state a single user leaving could cause
us to go and load a lot of membership events and then pull out
membership state in a large number of batches.

* Newsfile

* Update synapse/storage/persist_events.py

Co-Authored-By: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>

* Fix adding if too soon

* Update docstring

* Review comments

* Woops typo

Co-authored-by: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>

Fix log in message retention purge jobs

Co-Authored-By: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>

As per
https://github.com/matrix-org/matrix-doc/pull/2432#pullrequestreview-360566830,
make room alias lists accessible to users outside world_readable rooms.

... and set it everywhere it's called.

while we're here, rename it for consistency with `check_user_in_room` (and to
help check that I haven't missed any instances)

these were getting a bit unwieldy, so let's combine `check_joined_room` and
`check_user_was_in_room` into a single `check_user_in_room`.

per matrix-org/matrix-doc#2432

Rewrite _EventInternalMetadata to back it with a dict

Add mention and warning about ACME v1 deprecation to the TLS config

We do this by moving the recursive query to be fully in the DB.