* Fix rate limit metrics registering twice and misreporting

Fix https://github.com/matrix-org/synapse/issues/13641

* Fix lints

* Add changelog

* Document `metrics_name=None`.

Cross-ref #13525

Indroduced in #11846.

Fix:

 - https://github.com/matrix-org/synapse/pull/13535#discussion_r949582508
 - https://github.com/matrix-org/synapse/pull/13533#discussion_r949577244

`synapse.api.auth.Auth` cleanup: make permission-related methods use `Requester` instead of the `UserID` (#13024)

Part of #13019

This changes all the permission-related methods to rely on the Requester instead of the UserID. This is a first step towards enabling scoped access tokens at some point, since I expect the Requester to have scope-related informations in it.

It also changes methods which figure out the user/device/appservice out of the access token to return a Requester instead of something else. This avoids having store-related objects in the methods signatures.

Complement PR: https://github.com/matrix-org/complement/pull/450

As suggested in
https://github.com/matrix-org/matrix-spec-proposals/pull/2716#discussion_r941444525

Implement MSC3852: Expose `last_seen_user_agent` to users for their own devices; also expose to Admin API (#13549)

Uses Redis replication in additional test cases (instead of
TCP replication). A small step towards dropping TCP replication.

Fix validation problem that occurs when a user tries to deactivate their account or change their password. (#13563)

Follow-up to https://github.com/matrix-org/synapse/pull/13533

Part of https://github.com/matrix-org/synapse/issues/13356

Signed-off-by: Sean Quah <seanq@matrix.org>

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

Track number of hosts affected by the rate limiter so we can differentiate one really noisy homeserver from a general ratelimit tuning problem across the federation.

Follow-up to https://github.com/matrix-org/synapse/pull/13534

Part of https://github.com/matrix-org/synapse/issues/13356

Closes #13415.

Signed-off-by: Ayush Anand <iamayushanand@gmail.com>

Use a state filter or accept partial state in a few places where we
request state, to avoid blocking.

To make lazy-loading `/sync`s work, we need to provide the memberships
of event senders, which are not guaranteed to be in the room state.
Instead we dig through auth events for memberships to present to
clients. The auth events of an event are guaranteed to contain a
passable membership event, otherwise the event would have been rejected.

Note that this only covers the common code paths encountered during
testing. There has been no exhaustive checking of all sync code paths.

Fixes #13146.

Signed-off-by: Sean Quah <seanq@matrix.org>

Related to https://github.com/matrix-org/synapse/pull/13499

Part of https://github.com/matrix-org/synapse/issues/13356

Fix a bug in the `/event_reports` Admin API which meant that the total count could be larger than the number of results you can actually query for. (#13525)

Co-authored-by: Brendan Abolivier <babolivier@matrix.org>

Broke by #13522

It looks like we have some rules in the DB with a priority class less
than 0 that don't override the base rules. Before these were just
dropped, but #13522 made that a hard error.

Instrument the federation/backfill part of `/messages` so it's easier to follow what's going on in Jaeger when viewing a trace.

Split out from https://github.com/matrix-org/synapse/pull/13440

Follow-up from https://github.com/matrix-org/synapse/pull/13368

Part of https://github.com/matrix-org/synapse/issues/13356

Synapse does not currently support faster room joins on deployments with
workers.

Signed-off-by: Sean Quah <seanq@matrix.org>