Merge #103

103: WIP: refactor vscode extension r=aochagavia a=aochagavia

Todo:

- [x] Add more comments, so other people can find their way in the codebase
- [x] Resolve remaining tslint suggestions
- [ ] Integrate with CI

@matklad The standard configuration of tslint forbids using `console.log` and `console.error`. Is there any reason we are using those or can I remove them? If they are used for debugging purposes I would prefer to remove them and rely on vscode's excellent debugger.

Co-authored-by: Adolfo Ochagavía <aochagavia92@gmail.com>