Add some type hints to datastore (#12485)

changelog.d/12485.misc

synapse/storage/databases/main/__init__.py

synapse/storage/databases/main/appservice.py

synapse/storage/databases/main/deviceinbox.py

synapse/storage/databases/main/devices.py

synapse/storage/databases/main/group_server.py

synapse/storage/databases/main/keys.py

synapse/storage/databases/main/media_repository.py

synapse/storage/databases/main/presence.py

synapse/storage/databases/main/pusher.py

synapse/storage/databases/main/state.py

synapse/storage/databases/main/ui_auth.py