Adding ability to set hyperlinks as buttons in extensibility. (#16319)

* Adding option to treat hyperlinks as buttons

* Adding ext host endpoints for is button property in hyperlinks

* Removing isButton flag and plugging in aria role in the hyperlink component

* Removing attribute null check

extensions/sql-migration/src/dashboard/sqlServerDashboard.ts

@@ -566,6 +566,7 @@ export class DashboardWidget {
 		const refreshButton = view.modelBuilder.hyperlink().withProps({
 			label: loc.REFRESH,
 			url: '',
+			ariaRole: 'button',
 			CSSStyles: {
 				'text-align': 'right',
 				'font-size': '13px'

src/sql/workbench/browser/modelComponents/hyperlink.component.ts

@@ -21,7 +21,7 @@ import { ILogService } from 'vs/platform/log/common/log';
 
 @Component({
 	selector: 'modelview-hyperlink',
-	template: `<a [href]="url" [title]="title" [attr.aria-label]="ariaLabel" target="blank" [ngStyle]="CSSStyles" [class]="cssClass">{{label}}</a>`
+	template: `<a [href]="url" [title]="title" [attr.aria-label]="ariaLabel" [attr.role]="ariaRole" target="blank" [ngStyle]="CSSStyles" [class]="cssClass">{{label}}</a>`
 })
 export default class HyperlinkComponent extends TitledComponent<azdata.HyperlinkComponentProperties> implements IComponent, OnDestroy, AfterViewInit {
 	@Input() descriptor: IComponentDescriptor;