Support AD in cluster connection dialog (#7367)

- Use token API to get auth token before using other endpoints. Note this needs server updates before it'll work as expected (will only checkin after verifying this)
- Add auth option in controller UI and plumb through connection save, load, and uses of the controller API
Because the swagger spec is split in 2 created new file for the 2nd swagger spec including token auth endpoints. These come from a running cluster and instructions were updated to reflect this.

New UI Changes:
- Added authentication type field with "Basic" and "Windows Authentication" as the options
- Moved error notifications to the dialog instead of separate notification window. That's the recommended pattern
- Username / password aren't required for Windows Authentication. I couldn't find a way to change required status in form container on switching from Windows => Basic Auth so have error show on clicking OK. 
- Controller URL should use ":" not "," for IP:Port

extensions/big-data-cluster/src/bigDataCluster/auth.ts

@@ -0,0 +1,35 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the Source EULA. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import * as kerberos from 'kerberos';
+import * as vscode from 'vscode';
+
+export async function authenticateKerberos(hostname: string): Promise<string> {
+	const service = 'HTTP' + (process.platform === 'win32' ? '/' : '@') + hostname;
+	const mechOID = kerberos.GSS_MECH_OID_KRB5;
+	let client = await kerberos.initializeClient(service, { mechOID });
+	let response = await client.step('');
+	return response;
+}
+
+
+export type HostAndIp = { host: string, port: string };
+
+export function getHostAndPortFromEndpoint(endpoint: string): HostAndIp {
+	let authority = vscode.Uri.parse(endpoint).authority;
+	let hostAndPortRegex = /^(.*)([,:](\d+))/g;
+	let match = hostAndPortRegex.exec(authority);
+	if (match) {
+		return {
+			host: match[1],
+			port: match[3]
+		};
+	}
+	return {
+		host: authority,
+		port: undefined
+	};
+}
+