Part of #9744

Removes all redundant `# -*- coding: utf-8 -*-` lines from files, as python 3 automatically reads source code as utf-8 now.

`Signed-off-by: Jonathan de Jong <jonathan@automatia.nl&gt;`>

 - Update black version to the latest
 - Run black auto formatting over the codebase
    - Run autoformatting according to [`docs/code_style.md
`](https://github.com/matrix-org/synapse/blob/80d6dc9783aa80886a133756028984dbf8920168/docs/code_style.md)
 - Update `code_style.md` docs around installing black to use the correct version

We do it this way round so that only the "owner" can delete the access token (i.e. `/logout/all` by the "owner" also deletes that token, but `/logout/all` by the "target user" doesn't).

A future PR will add an API for creating such a token.

When the target user and authenticated entity are different the `Processed request` log line will be logged with a: `{@admin:server as @bob:server} ...`. I'm not convinced by that format (especially since it adds spaces in there, making it harder to use `cut -d ' '` to chop off the start of log lines). Suggestions welcome.

Don't fail /submit_token requests on incorrect session ID if request_token_inhibit_3pid_errors is turned on (#7991)

* Don't raise session_id errors on submit_token if request_token_inhibit_3pid_errors is set

* Changelog

* Also wait some time before responding to /requestToken

* Incorporate review

* Update synapse/storage/databases/main/registration.py

Co-authored-by: Andrew Morgan <1342360+anoadragon453@users.noreply.github.com>

* Incorporate review

Co-authored-by: Andrew Morgan <1342360+anoadragon453@users.noreply.github.com>

Signed-off-by: Manuel Stahl <manuel.stahl@awesome-technologies.de>

This encapsulates config for a given database and is the way to get new
connections.

Record how long an access token is valid for, and raise a soft-logout once it
expires.

The 'token' param is no longer used anywhere except the tests, so let's kill
that off too.

Allow for the creation of a support user.

A support user can access the server, join rooms, interact with other users, but does not appear in the user directory nor does it contribute to monthly active user limits.

When a user first syncs, we will send them a server notice asking them to
consent to the privacy policy if they have not already done so.

We might as well treat all refresh_tokens as invalid. Just return a 403 from
/tokenrefresh, so that we don't have a load of dead, untestable code hanging
around.

Still TODO: removing the table from the schema.

Add a 'devices' table to the storage, as well as a 'device_id' column to
refresh_tokens.

Allow the client to pass a device_id, and initial_device_display_name, to
/login. If login is successful, then register the device in the devices table
if it wasn't known already. If no device_id was supplied, make one up.

Associate the device_id with the access token and refresh token, so that we can
get at it again later. Ensure that the device_id is copied from the refresh
token to the access_token when the token is refreshed.

Removes device_id and ClientInfo

device_id is never actually written, and the matrix.org DB has no
non-null entries for it. Right now, it's just cluttering up code.

This doesn't remove the columns from the database, because that's
fiddly.

This allows refresh tokens to be exchanged for (access_token,
refresh_token).

It also starts issuing them on login, though no clients currently
interpret them.

We're about to have two kinds of token, access and refresh

Before, caches were global and so different instances of the stores
would share caches. This caused problems in the unit tests.

Don't test exact equality of the list: as long as it has the fields we expect, that's just fine. I added the user_id (as in database pkey) and it broke: no point testing what that comes out as: it's determined by the db.