Bug/accessibility 5 (#7008)

* fixing 6946 and 6796(second part)

* fix for https://github.com/microsoft/azuredatastudio/issues/6726

* comments cleanup

* taking PR comments

* adding strong border for HC focus

* convert to string template

src/sql/platform/dialog/browser/dialogPane.ts

@@ -79,7 +79,7 @@ export class DialogPane extends Disposable implements IThemable {
 							tabContainer.style.display = 'block';
 						},
 						layout: (dimension) => { this.getTabDimension(); },
-						focus: () => { }
+						focus: () => { this.focus(); }
 					}
 				});
 			});