Native VSCode keybindings

Our VSCode extension should respect the key binding of the environment (Windows, Mac, Linux) especially for Copy and Paste, Undo & Redo operations.
It is expected that some of them will be already working, since the default modifier key for LInux and Windows is Ctrl. On Mac, however, copy/paste commands are done with Cmmd + C, so we'll probably have some work to do.