add package-name in http-client-csharp-mgmt

Author: Shane Fu

specification/storagediscovery/Microsoft.StorageDiscovery.Management/tspconfig.yaml

@@ -14,6 +14,7 @@ options:
     examples-dir: "{project-root}/examples"
   "@azure-typespec/http-client-csharp-mgmt":
     namespace: "Azure.ResourceManager.StorageDiscovery"
+    package-name: {namespace}
     emitter-output-dir: "{output-dir}/{service-dir}/{namespace}"
   "@azure-tools/typespec-java":
     emitter-output-dir: "{output-dir}/{service-dir}/azure-resourcemanager-storagediscovery"