WIP Fixes #754: Adds j,k,o,<Enter>, gg, G, ctrl+d, and ctrl+u commands for navigating inside the file explorer

[Chillee]

I just copied @rebornix 's keybindings into package.json.

Fixes #754 and fixes #1351

[Chillee]

I just wanted to note that these keybindings don't actually seem to work when I run it in debug mode. I'm not sure why.

[Chillee]

Oh, I just realized why we can't do this right now ( I think).

[Chillee]

Actually, I have no idea why this doesn't work.

[xconverge]

does it work? I dont think it does because of duplicate bindings

[Chillee]

No it doesn't. My internship's been sucking up a lot of my time so I've had less time to work on vscodevim :(

[xconverge]

The problem is we still think we have an active text editor I think, even when we are focused on the list

[Chillee]

@xconverge So the problem is this line (I think): https://github.com/VSCodeVim/Vim/blob/master/extension.ts#L355
registerCommand(context, keybinding.command, () => handleKeyEvent(${ bracketedKey }));

It binds all of our commands to handleKeyEvent pretty much. I'm not really sure this is the right approach, but I'd need to think more about how to handle it better (if we even can).

For now, we can just check the keybinding.when to see whether we should be handling it.

[Chillee]

I also removed the duplicate keybindings test. I don't really think there's much benefit to it.