Clean up newline quote marks around the codebase (#6362)

changelog.d/6362.misc

synapse/app/federation_sender.py

synapse/appservice/api.py

synapse/config/appservice.py

synapse/config/room_directory.py

synapse/config/server.py

synapse/federation/persistence.py

synapse/federation/sender/__init__.py

synapse/federation/sender/transaction_manager.py

synapse/handlers/directory.py

synapse/http/servlet.py

synapse/push/httppusher.py

synapse/push/mailer.py

synapse/rest/media/v1/preview_url_resource.py

synapse/server_notices/consent_server_notices.py

synapse/storage/_base.py

synapse/storage/data_stores/main/deviceinbox.py

synapse/storage/data_stores/main/end_to_end_keys.py

synapse/storage/data_stores/main/events.py

synapse/storage/data_stores/main/filtering.py