Add focus logic to the tabbed panel (#5649)

* add focus logic to the tabbed panel

* change enter to be on key up

* fix  tests

src/sql/workbench/parts/queryPlan/electron-browser/queryPlan.ts

@@ -64,6 +64,10 @@ export class QueryPlanView implements IPanelView {
 		this.container.style.height = dimension.height + 'px';
 	}
 
+	public focus() {
+		this.container.focus();
+	}
+
 	public clear() {
 		if (this.qp) {
 			this.qp.xml = undefined;