more typings work around data query and data source

packages/grafana-ui/src/types/datasource.ts

@@ -7,8 +7,26 @@ export interface DataQueryResponse {
 }
 
 export interface DataQuery {
+  /**
+   * A - Z
+   */
   refId: string;
+
+  /**
+   * true if query is disabled (ie not executed / sent to TSDB)
+   */
   hide?: boolean;
+
+  /**
+   * Unique, guid like, string used in explore mode
+   */
+  key?: string;
+
+  /**
+   * For mixed data sources the selected datasource is on the query level.
+   * For non mixed scenarios this is undefined.
+   */
+  datasource?: string | null;
 }
 
 export interface DataQueryOptions<TQuery extends DataQuery = DataQuery> {