Integrate first SQL Notebooks Bits into Master (#3679)

* First crack tsql notebook (no output rendered yet)

* getting messages back

* intellisense working first cell, no connection errors

* sql notebook cell output functioning

* Latest SQL noteobook changes

* Undo change to launch.json

* Plumbing providers through

* Kernels shown from multiple providers, can switch between them. No mementos yet

* Ensure we have a feature flag for SQL notebooks, ensure existing functionality still works

* Fix tslint duplicate imports issue

* Addressing PR comments

* second round of PR feedback to cleanup notebook service manager code

* merge latest from master

src/sql/parts/notebook/models/modelInterfaces.ts

@@ -249,9 +249,9 @@ export interface INotebookModel {
 	readonly languageInfo: nb.ILanguageInfo;
 
 	/**
-	 * The notebook service used to call backend APIs
+	 * All notebook managers applicable for a given notebook
 	 */
-	readonly notebookManager: INotebookManager;
+	readonly notebookManagers: INotebookManager[];
 
 	/**
 	 * Event fired on first initialization of the kernel and
@@ -299,6 +299,11 @@ export interface INotebookModel {
 	 */
 	trustedMode: boolean;
 
+	/**
+	 * Current notebook provider id
+	 */
+	providerId: string;
+
 	/**
 	 * Change the current kernel from the Kernel dropdown
 	 * @param displayName kernel name (as displayed in Kernel dropdown)
@@ -411,7 +416,8 @@ export interface INotebookModelOptions {
 	 */
 	factory: IModelFactory;
 
-	notebookManager: INotebookManager;
+	notebookManagers: INotebookManager[];
+	providerId: string;
 
 	notificationService: INotificationService;
 	connectionService: IConnectionManagementService;