Create a Visual Studio Code plugin

[obscurerichard]

Is your feature request related to a problem? Please describe.
A huge proportion of the the worldwide developer population uses Visual Studio Code (VSCode) to write Python, and could benefit from FawltyDeps.

Describe the solution you'd like
Create a VSCode plugin that executes FawltyDeps, much as existing plugins for other linters (black, isort, etc) do.

Describe alternatives you've considered
Create an emacs plugin (see #435)
Create CI plugins (see #170)

Additional context
This was contemplated in the original design document for FawltyDeps but not added to the backlog.