Pass room_version into `event_from_pdu_json`

Limit the maximum number of events requested when backfilling events.

It's called from all over the shop, so this one's a bit messy.

... which allows us to sanity-check the create event.

A lot of the things we log at INFO are now a bit superfluous, so lets
make them DEBUG logs to reduce the amount we log by default.

Co-Authored-By: Brendan Abolivier <babolivier@matrix.org>
Co-authored-by: Brendan Abolivier <github@brendanabolivier.com>

pass room versions around

Synapse 1.10.0rc2 (2020-02-06)
==============================

Bugfixes
--------

- Fix an issue with cross-signing where device signatures were not sent to remote servers. ([\#6844](https://github.com/matrix-org/synapse/issues/6844))
- Fix to the unknown remote device detection which was introduced in 1.10.rc1. ([\#6848](https://github.com/matrix-org/synapse/issues/6848))

Internal Changes
----------------

- Detect unexpected sender keys on remote encrypted events and resync device lists. ([\#6850](https://github.com/matrix-org/synapse/issues/6850))

Add quotes around the pip install target to avoid my shell complaining

Port much of `synapse.federation.federation_client` to async/await

Co-Authored-By: Erik Johnston <erik@matrix.org>

If they don't then the device lists are probably out of sync.

add device signatures to device key query results

* Reduce tnx performance logging to DEBUG
* Changelog.d

We're going to need this so that we can figure out how to handle redactions when fetching events from the database.

We were looking at the wrong event type (`m.room.encryption` vs
`m.room.encrypted`).

Also fixup the duplicate `EvenTypes` entries.

Introduced in #6776.

add device signatures to device key query results

Port much of `synapse.handlers.federation` to async/await.