Describe which rate limiter was hit in logs (#16135)

changelog.d/16135.misc

synapse/api/errors.py

synapse/api/ratelimiting.py

synapse/config/ratelimiting.py

synapse/handlers/auth.py

synapse/handlers/devicemessage.py

synapse/handlers/identity.py

synapse/handlers/room_member.py

synapse/handlers/room_summary.py

synapse/http/server.py

synapse/rest/client/login.py

synapse/rest/client/login_token_request.py

synapse/rest/client/register.py

synapse/server.py

synapse/util/ratelimitutils.py

tests/api/test_errors.py

tests/api/test_ratelimiting.py

tests/config/test_ratelimiting.py