Adding database backup and accounts page to migration wizard (#13764)

* Added localized strings
Created a db backup page
added radio buttons

* created components for database backup page

* Added account selection page

* Added accounts page

* Some more work done

- Added page validations
- Almost done with db backup except for a few api calls.

* Some more progress
added graph api for storage account

* Finished hooking up all the endpoints on db page.

* Some code fixed and refactoring

* Fixed a ton of validation bugs

* Added common localized strings to the constants file

* some code cleanup

* changed method name to makeHttpGetRequest

* change http result class name

* Added return types and return values to the functions

* removed void returns

* Added more return types and values

* Storing accounts in the map with ids as key
Fixed a bug in case of no subscriptions found

* cleaning up the code

* Fixed localized strings

* Added comments to get request api
Added validation logic to database backup page
removed unnecessary page validations.

* Added some get resource functions in azure core

* Changed thenable to promise

* Added arm calls for file shares and blob storage

* Added field specific validation error message

* Added examples in validation error message.

* Fixed some typings and localized string

* Added live validations to dropdowns

* Fixed method name to getSQLVMservers

* Using older storage package

* Update typings/namings (#13767)

* Update typings

* more typings fixes

* switched fileshares and blobcontainers api to http requests

* removed the extra line

* Adding resource graph documentation link as a comment

* remove makeHttpRequest api from azurecore

Co-authored-by: Charles Gagnon <chgagnon@microsoft.com>

extensions/sql-migration/src/models/migrationWizardPage.ts

@@ -7,7 +7,7 @@ import * as azdata from 'azdata';
 import { MigrationStateModel, StateChangeEvent } from './stateMachine';
 export abstract class MigrationWizardPage {
 	constructor(
-		private readonly wizard: azdata.window.Wizard,
+		protected readonly wizard: azdata.window.Wizard,
 		protected readonly wizardPage: azdata.window.WizardPage,
 		protected readonly migrationStateModel: MigrationStateModel
 	) { }