Plugins: Add secure JSON fields to plugin setting DTO (#55313)

* add secure JSON fields to plugin setting DTO

* add nil pointer fix

* adding secureJsonFields to the plugin meta.

Co-authored-by: Marcus Andersson <marcus.andersson@grafana.com>

packages/grafana-data/src/types/plugin.ts

@@ -69,6 +69,7 @@ export interface PluginMeta<T extends KeyValue = {}> {
   // Filled in by the backend
   jsonData?: T;
   secureJsonData?: KeyValue;
+  secureJsonFields?: KeyValue<boolean>;
   enabled?: boolean;
   defaultNavUrl?: string;
   hasUpdate?: boolean;