Lots of orphaned progress notifications after interactive window fails to open

[mjbvz]

Issue Type: Bug

Repro
Same initial steps as microsoft/vscode-python#14509:

1. Install python extension
2. Run something in the python terminal
3. Now open python interactive window using run in interactive window
4. See alert about installing ipykernel
5. Click button to install

The install should never complete. Now:

1. Click the cancel buttons on the install notifications.
2. See some error notifications
3. The interactive window closes
4. Click on VS Code's notifications

Bug
There are still progress tasks running:

Specifically Connecting to IPython kernel: Fetching Kernels and Executing Cell. I don't seem to be able to cancel or dismiss either of these

Extension version: 2020.9.114305
VS Code version: Code - Insiders 1.51.0-insider (7a3bdf4ee9588755d447aa1c3b5db4a123fc11a9, 2020-10-23T07:32:22.213Z)
OS version: Darwin x64 19.6.0

[joyceerhl]

Thanks for reporting this @mjbvz. The 'Connecting to IPython kernel' message is created on a progress indicator that isn't cancellable, so at minimum we should pass the cancelToken if any here to createProgressIndicator:

    protected async createNotebookInstance(
        resource: Resource,
        identity: vscode.Uri,
        disableUI?: boolean,
        notebookMetadata?: nbformat.INotebookMetadata,
        cancelToken?: CancellationToken
    ): Promise<INotebook> {
        traceInfo(`Creating raw notebook for ${identity.toString()}`);
        const notebookPromise = createDeferred<INotebook>();
        this.setNotebook(identity, notebookPromise.promise);

        const progressReporter = !disableUI
            ? this.progressReporter.createProgressIndicator(localize.DataScience.connectingIPyKernel())
            : undefined;

[talk2sunil83]

Same with:

Version: 1.51.0-insider (user setup)
Commit: e5c0007ce0e9a3816679cba674d03376c03726e3
Electron: 9.3.3
Chrome: 83.0.4103.122
Node.js: 12.14.1
V8: 8.3.110.13-electron.0
OS: Windows_NT x64 10.0.20226

Python Extn : v2020.9.114305
Pylance: v2020.10.2

[DonJayamanne]

Need to refactor the code and clean up how we start kernels.

[DonJayamanne]

Should not be an issue anymore, we've refactored this code.
Moving to validate.