Add integration test for opening a ipynb file

extensions/vscode-api-tests/testWorkspace/test.ipynb

@@ -0,0 +1,53 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "source": [
+    "## Header"
+   ],
+   "metadata": {}
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "source": [
+    "print('hello 1')\n",
+    "print('hello 2')"
+   ],
+   "outputs": [
+    {
+     "output_type": "stream",
+     "name": "stdout",
+     "text": [
+      "hello 1\n",
+      "hello 2\n"
+     ]
+    }
+   ],
+   "metadata": {}
+  }
+ ],
+ "metadata": {
+  "interpreter": {
+   "hash": "815c6b7592bf74925ca002a1774bcf064bae9d6a27e7933fd9109275fb484258"
+  },
+  "kernelspec": {
+   "name": "python3",
+   "display_name": "Python 3.9.5 64-bit ('myvenv': venv)"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.9.5"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 4
+}