Decouple `synapse.api.auth_blocking.AuthBlocking` from `synapse.api.auth.Auth`. (#13021)

changelog.d/13021.misc

synapse/api/auth.py

synapse/handlers/auth.py

synapse/handlers/message.py

synapse/handlers/register.py

synapse/handlers/room.py

synapse/handlers/sync.py

synapse/server.py

synapse/server_notices/resource_limits_server_notices.py

tests/api/test_auth.py

tests/handlers/test_auth.py

tests/handlers/test_register.py

tests/handlers/test_sync.py

tests/server_notices/test_resource_limits_server_notices.py