Convert stream database to async/await. (#8074)

changelog.d/8074.misc

synapse/api/filtering.py

synapse/api/presence.py

synapse/federation/send_queue.py

synapse/federation/sender/__init__.py

synapse/federation/sender/per_destination_queue.py

synapse/handlers/presence.py

synapse/storage/databases/main/presence.py

synapse/storage/databases/main/stream.py

tests/handlers/test_presence.py

tests/storage/test_purge.py