[Feature] Support Databrick Notebook (.py) <> Jupyter Notebook (.ipynb) conversion

[lukeSmth]

The extension currently supports executing Databricks Notebooks in .py format interactively using VSCode's interactive window. An additional access mode could use jupytext and nbconvert to convert Databricks Notebooks to .ipynb. This conversion could be ephemeral, only existing while open the file is open in VSCode, or more permanent. In either case, changes to the .ipynb file could be synced with the .py file on save. The .ipynb could be added to the the user's .gitignore by default.

See the Jupytext for VSCode extension for an example. If a nbformat template for Databricks Notebook (.py) <> Jupyter Notebook (.ipynb) conversions was published and Jupytext for VSCode was updated to support custom formats then no further work would be needed.

The ideal state would be support within the Databricks VSCode extension and a published conversion template. The template would allow integration into the existing notebook conversion ecosystem.

[MrTeale]

+1 on this. This is actually one of the few blockers I have to developing solely in VSCode rather than the UI.

@kartikgupta-db - If you have a rough understanding of what would need to change for this to be implemented and would accept a PR, I'd be willing to have a go. Just need some guidance on getting started