Add datavirtualization extension (#21594)

* initial

* cleanup

* Add typings ref

* fix compile

* remove unused

* add missing

* another unused

* Use newer vscodetestcover

* newer dataprotocol

* format

* cleanup ignores

* fix out path

* fix entry point

* more cleanup

* Move into src folder

* Handle service client log messages

* remove unused

extensions/datavirtualization/src/wizards/wizardPageWrapper.ts

@@ -0,0 +1,23 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the Source EULA. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import * as azdata from 'azdata';
+import { VirtualizeDataInput } from '../services/contracts';
+
+export interface IWizardPageWrapper {
+	// Returns underlying wizard page object.
+	getPage(): azdata.window.WizardPage;
+
+	// Called for the current page after clicking the Wizard's Next button.
+	// Returns boolean indicating whether validation was successful and thus
+	// if page can be changed.
+	validate(): Promise<boolean>;
+
+	// Updates the wizard page by retrieving current info from the backing data model.
+	updatePage(): Promise<void>;
+
+	// Adds this page's input contributions to the provided data input object
+	getInputValues(existingInput: VirtualizeDataInput): void;
+}