change SynapseClient to MonitoringClient (#10168)

Author: sunsw1994

specification/synapse/data-plane/Microsoft.Synapse/preview/2019-11-01-preview/monitoring.json

@@ -2,7 +2,7 @@
   "swagger": "2.0",
   "info": {
     "version": "2019-11-01-preview",
-    "title": "SynapseClient"
+    "title": "MonitoringClient"
   },
   "x-ms-parameterized-host": {
     "hostTemplate": "{endpoint}",