Strip .ipynb extension for display in header and tab title

[JasonWeill]

Fixes #160 by stripping only .ipynb from the end of filenames displayed in the workbook title.

Before the change, "Untitled.ipynb" appears to the right of the Jupyter logo in the top area and in the tab title.

After the change, "Untitled" appears in these areas.

[github-actions]

👈 Launch RetroLab on Binder

[JasonWeill]

The "enforce-label" job failed, but the enhancement label is present on this issue.

[JasonWeill]

Can someone please assign this issue to me?

[jtpio]

Thanks @jweill-aws!

Mind posting a small before / after screenshot in the top comment for reference?

[jtpio]

We could also apply the same logic to the browser tab title:

Which is updated in this plugin:

retrolab/packages/application-extension/src/index.ts

Lines 371 to 404 in 4fd58de

	/**
	* A plugin to display the document title in the browser tab title
	*/
	const tabTitle: JupyterFrontEndPlugin<void> = {
	id: '@retrolab/application-extension:tab-title',
	autoStart: true,
	requires: [IRetroShell],
	activate: (app: JupyterFrontEnd, shell: IRetroShell) => {
	const setTabTitle = () => {
	const current = shell.currentWidget;
	if (current instanceof ConsolePanel) {
	const update = () => {
	const title =
	current.sessionContext.path || current.sessionContext.name;
	const basename = PathExt.basename(title);
	document.title = basename;
	};
	current.sessionContext.sessionChanged.connect(update);
	update();
	return;
	} else if (current instanceof DocumentWidget) {
	const update = () => {
	const basename = PathExt.basename(current.context.path);
	document.title = basename;
	};
	current.context.pathChanged.connect(update);
	update();
	}
	};
	shell.currentChanged.connect(setTabTitle);
	setTabTitle();
	}
	};

[jtpio]

Thanks!