Rename deletions to redactions

synapse/api/auth.py

synapse/api/events/__init__.py

synapse/api/events/factory.py

synapse/api/events/room.py

synapse/api/events/utils.py

synapse/handlers/room.py

synapse/rest/room.py

synapse/storage/__init__.py

synapse/storage/_base.py

synapse/storage/room.py

synapse/storage/roommember.py

synapse/storage/schema/deletions.sql

synapse/storage/schema/delta/v4.sql

synapse/storage/schema/im.sql

synapse/storage/schema/redactions.sql

synapse/storage/stream.py