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/workbench/contrib/notebook/browser/models/notebookInput.ts

@@ -254,6 +254,10 @@ export abstract class NotebookInput extends EditorInput {
 		return this.resource;
 	}
 
+	public get notebookModel(): INotebookModel | undefined {
+		return this._model.getNotebookModel();
+	}
+
 	public get notebookFindModel(): NotebookFindModel {
 		if (!this._notebookFindModel) {
 			this._notebookFindModel = new NotebookFindModel(this._model.getNotebookModel());