We assume, as we did before, that users bound their threepid to one of
the trusted identity servers. So we simply fill the new table with all
threepids in `user_threepids` joined with the trusted identity servers.

By default the homeserver will use the identity server used during the
binding of the 3PID to unbind the 3PID. However, we need to allow
clients to explicitly ask the homeserver to unbind via a particular
identity server, for the case where the 3PID was bound out of band from
the homeserver.

Implements MSC915.

This changes the behaviour from using the server specified trusted
identity server to using the IS that used during the binding of the
3PID, if known.

This is the behaviour specified by MSC1915.

This will then be used to know which IS to default to when unbinding the
threepid.

Feature/fix small stuff in docker readme.md

Signed-off-by: Jurrie Overgoor <1213142+Jurrie@users.noreply.github.com>

Signed-off-by: Jurrie Overgoor <1213142+Jurrie@users.noreply.github.com>

Combine the CurrentStateDeltaStream into the EventStream

Refactors to replication stream row update/parsing

Remove log line for password.

This PR allows password provider modules to bind email addresses when a user is registering and is motivated by matrix-org/matrix-synapse-ldap3#58

Use event streams to calculate presence

Split up replication.tcp.streams into smaller files

... as a precursor to combining it with the CurrentStateDelta stream.

We're about to turn it straight into a JSON object anyway so building a
ROW_TYPE is a bit pointless, and reduces flexibility in the update_function.

This will allow individual stream classes to override how a row is parsed.

Primarily this fixes a bug in the handling of remote users joining a
room where the server sent out the presence for all local users in the
room to all servers in the room.

We also change to using the state delta stream, rather than the
distributor, as it will make it easier to split processing out of the
master process (as well as being more flexible).

Finally, when sending presence states to newly joined servers we filter
out old presence states to reduce the number sent. Initially we filter
out states that are offline and have a last active more than a week ago,
though this can be changed down the line.

Fixes #3962

Adds a new method, check_3pid_auth, which gives password providers
the chance to allow authentication with third-party identifiers such
as email or msisdn.

Redo of https://github.com/matrix-org/synapse/pull/4840

`__str__` depended on `self.addr`, which was absent from
ClientReplicationStreamProtocol, so attempting to call str on such an object
would raise an exception.

We can calculate the peer addr from the transport, so there is no need for addr
anyway.

Make sure that they are sent correctly over the replication stream.

Fixes: #4898

I don't have a database with the same name as my user, so leaving the database
name unset fails.

While we're at it, clear out some unused stuff in the test setup.