Split presence out of master (#9820)

changelog.d/9820.feature

scripts/synapse_port_db

synapse/app/generic_worker.py

synapse/config/workers.py

synapse/handlers/presence.py

synapse/replication/http/_base.py

synapse/replication/slave/storage/presence.py

synapse/replication/tcp/handler.py

synapse/replication/tcp/streams/_base.py

synapse/rest/client/v1/presence.py

synapse/server.py

synapse/storage/databases/main/__init__.py

synapse/storage/databases/main/presence.py

...bases/main/schema/delta/59/12presence_stream_instance.sql

...hema/delta/59/12presence_stream_instance_seq.sql.postgres

tests/app/test_frontend_proxy.py

tests/rest/client/v1/test_presence.py