Notebooks: Use new Python installation after configuration change (#14765)

* start new jupyter server

* restart session working (removed extra code)

* only restart server once

* shutdown session first then stop server

* add comments remove extra lines

* add comment

* fix test

* only restart jupyter sessions

* Dispose jupytersessionmanager and create new one

* move restart server logic out of notebookmodel

* move methods to azdata proposed

* pr comment

src/sql/azdata.proposed.d.ts

@@ -51,6 +51,16 @@ declare module 'azdata' {
 		export type ICellAttachments = { [key: string]: ICellAttachment };
 		export type ICellAttachment = { [key: string]: string };
 
+		export interface SessionManager {
+			/**
+			 * Shutdown all sessions.
+			 */
+			shutdownAll(): Thenable<void>;
+			/**
+			 * Disposes the session manager.
+			 */
+			dispose(): void;
+		}
 	}
 
 	export type SqlDbType = 'BigInt' | 'Binary' | 'Bit' | 'Char' | 'DateTime' | 'Decimal'