Run `isort`, `flake8` and `black` over the `contrib/` directory and `synctl` script. The latter was already being done in CI, but now the linting script does it too.

Fixes https://github.com/matrix-org/synapse/issues/7910

* Fix seven contrib files with Python syntax errors

Signed-off-by: cclauss <cclauss@me.com>

fix the copyright holder from matrix.org to OpenMarket Ltd, as matrix.org hasn't been incorporated in time for launch.

change the world: make the default matrix API URL prefix /_matrix rather than /matrix to make it easier for existing websites to mount a HS in their namespace without collisions.

perl -pi -e 's#/matrix#/_matrix#g' ./cmdclient/console.py ./docs/client-server/howto.rst ./docs/client-server/specification.rst ./docs/client-server/swagger_matrix/directory ./docs/client-server/swagger_matrix/events ./docs/client-server/swagger_matrix/login ./docs/client-server/swagger_matrix/presence ./docs/client-server/swagger_matrix/profile ./docs/client-server/swagger_matrix/registration ./docs/client-server/swagger_matrix/rooms ./docs/server-server/specification.rst ./graph/graph.py ./jsfiddles/create_room_send_msg/demo.js ./jsfiddles/event_stream/demo.js ./jsfiddles/example_app/demo.js ./jsfiddles/register_login/demo.js ./jsfiddles/room_memberships/demo.js ./synapse/api/urls.py ./tests/federation/test_federation.py ./tests/handlers/test_presence.py ./tests/handlers/test_typing.py ./tests/rest/test_events.py ./tests/rest/test_presence.py ./tests/rest/test_profile.py ./tests/rest/test_rooms.py ./webclient/components/fileUpload/file-upload-service.js ./webclient/components/matrix/matrix-service.js

add in copyrights to everything, not just the synapse subdir, and add a copyrighter.pl whilst we're at it