Tracking issue: Code refactorings

[Hirevo]

This is a tracking issue for the refactors that will happen for the extension.

I think the code style is pretty poor at the moment.
Some things to fix includes:

• Some things are inconsistent (like double quotes vs single quotes)
• Some code could be written to be more terse, more readable and more maintanable than it currently is.
• The filenames are confusing, I don't even know why I did it this way.
• Explore the current idiomatic way to do file edits in VSCode (is there new/better APIs to use ?)