VSCode Compatibility

[NateLanza]

Does this PR close any open issues?

Closes #112

Give a longer description of what this PR addresses and why it's needed

Removes all imports from Jupyterlab code to make Persist compatible with VSCode:

• Instead of storing edits in cell metadata, now creates a .jupersist file in the same directory as the jupyter notebook, using the same name as the notebook (minus the .ipynb extension) to store provenance data. This file MUST be moved alongside the notebook file for provenance data to persist.
• Breaks annotations; a later update will have to re-integrate these
• Removes some functionality that relied on Jupyterlab code, such as automatically inserting a dataframe name in a new cell and other functions which require modifying the notebook.
• Users should note that VSCode's Python linter doesn't recognize dataframe variable names generated from Persist, however, cells containing code referencing these vars still execute normally at runtime as long as the Persist cell has been executed first
• Uninstalls commitlint; this is unnecessary

Provide pictures/videos of the behavior before and after these changes (optional)

Have you added or updated relevant tests?

• Yes
• No changes are needed

Have you added or updated relevant documentation?

• Yes
• No changes are needed

Are there any additional TODOs before this PR is ready to go?

TODOs:

• Create issue for annotations

[github-actions]

👈 Launch a Binder on branch visdesignlab/persist/VSCode-integration