Add title property for data grid providers (#13155)

src/sql/azdata.proposed.d.ts

@@ -257,6 +257,11 @@ declare module 'azdata' {
 		 * Gets the list of data grid columns for this provider
 		 */
 		getDataGridColumns(): Thenable<DataGridColumn[]>;
+
+		/**
+		 * The user visible string to use for the title of the grid
+		 */
+		title: string;
 	}
 
 	export interface HyperlinkComponent {