VSCE: Create development script for VS Code extension

Created by: tjkandala

Currently, developers have to manually run:

type generation -> webpack build -> vs code debug in that order each time they make changes to the VS Code extension.

Try to make VS Code extension development as easy as possible with a simple development script. On code changes, developers should be able to reload the development window (bonus if possible: hot reloading) and see the changes reflected in the extension.

Considerations:

• Maintain separate build and dev scripts to utilize the correct webpack mode
• I believe we need to use a more permissive CSP for our webviews in development mode, so we need to figure out a way to maintain a restrictive CSP in production mode (could use DefinePlugin)