Jupyter extension

[RubenPants]

If with_jupyter_lab=1, then the jupyter widget should be installed in devcontainer.json:

...
    "customizations": {
        "vscode": {
            "extensions": [
                "charliermarsh.ruff",
                "ms-python.python",
                "ms-toolsai.jupyter",  // TODO: Add Jupyter!
                "ryanluker.vscode-coverage-gutters",
                "tamasfe.even-better-toml",
                "visualstudioexptteam.vscodeintellicode"
            ],
...