HAproxy reverse proxy guide update to stop sending IPv4-mapped address to HS.

Co-authored-by: Shay <hillerys@element.io>

Resolves #10339

* Formally type the UserProfile in user searches
* export UserProfile in synapse.module_api
* Update docs

Co-authored-by: Sean Quah <8349537+squahtx@users.noreply.github.com>

Fixes https://github.com/matrix-org/synapse/issues/12205

Co-authored-by: Patrick Cloke <clokep@users.noreply.github.com>

This includes the `typing`, `to_device`, `account_data`, `receipts`, and `presence`
streams (really anything except the `events` stream).

Remove workaround introduced in Synapse v1.50.0rc1 for Mjolnir compatibility. Breaks compatibility with Mjolnir v1.3.1 and earlier. (#11700)

Some stuff that came up while we were talking about #12173.

Add third_party module callbacks to check if a user can delete a room and deactivate a user (#12028)

* Add check_can_deactivate_user

* Add check_can_shutdown_rooms

* Documentation

* callbacks, not functions

* Various suggested tweaks

* Add tests for test_check_can_shutdown_room and test_check_can_deactivate_user

* Update check_can_deactivate_user to not take a Requester

* Fix check_can_shutdown_room docs

* Renegade and use `by_admin` instead of `admin_user_id`

* fix lint

* Update docs/modules/third_party_rules_callbacks.md

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

* Update docs/modules/third_party_rules_callbacks.md

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

* Update docs/modules/third_party_rules_callbacks.md

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

* Update docs/modules/third_party_rules_callbacks.md

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

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

* Rewrites the demo documentation to be clearer, accurate, and moves it to our documentation tree.
* Improvements to the demo scripts:
	* `clean.sh` now runs `stop.sh` first to avoid zombie processes.
	* Uses more modern Synapse configuration (and removes some obsolete configuration).
	* Consistently use the HTTP ports for server name, etc.
	* Remove the `demo/etc` directory and place everything into the `demo/808x` directories.

* Rename scripts-dev to have suffices

* Update references to `scripts-dev`

* Changelog

* These scripts don't pass mypy

* Two scripts are basically entry_points already
* Move and rename scripts/* to synapse/_scripts/*.py
* Delete sync_room_to_group.pl
* Expose entry points in setup.py
* Update linter script and config
* Fixup scripts & docs mentioning scripts that moved

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

...and various code supporting it.

The /spaces endpoint was from an old version of MSC2946 and included
both a Client-Server and Server-Server API. Note that the unstable
/hierarchy endpoint (from the final version of MSC2946) is not yet
removed.

And clean-up the endpoints which should be routed to workers.

The presence of this method was confusing, and mostly present for backwards
compatibility. Let's get rid of it.

Part of #11733

Since it is reasonable to give a future or past auth provider,
which might not be in the current configuration.

Co-authored-by: Patrick Cloke <clokep@users.noreply.github.com>

Co-authored-by: Patrick Cloke <clokep@users.noreply.github.com>

Co-authored-by: Patrick Cloke <clokep@users.noreply.github.com>

The StreamHandler takes a stream parameter, not location.