Use symbolic names for replication stream names (#7768)

changelog.d/7768.misc

synapse/replication/slave/storage/account_data.py

synapse/replication/slave/storage/deviceinbox.py

synapse/replication/slave/storage/groups.py

synapse/replication/slave/storage/presence.py

synapse/replication/slave/storage/push_rule.py

synapse/replication/slave/storage/pushers.py

synapse/replication/slave/storage/receipts.py

synapse/replication/slave/storage/room.py

synapse/storage/data_stores/main/cache.py

synapse/storage/data_stores/main/events_worker.py