Add evaluateForEffect method to support expression evaluation for side effects

extension/src/VisualizationWatchModel/VisualizationWatchModelImpl.ts

@@ -44,6 +44,12 @@ export class VisualizationWatchModelImpl implements VisualizationWatchModel {
 	public getCompletions(text: string, column: number): Promise<CompletionItem[]> {
 		return this.visualizationBackend.getCompletions(text, column);
 	}
+
+	public evaluateForEffect(
+		expression: string
+	): Promise<{ result: string } | { error: string }> {
+		return this.visualizationBackend.evaluateForEffect(expression);
+	}
 }
 
 class ObservableVisualizationWatch implements VisualizationWatch {