fix: support up/down for cmdline history

[theol0403]

Fixes #288

As of microsoft/vscode#211756, arrow keys are now bindable in quickpick.

[theol0403]

I think more thought should be put towards how we handle navigating the suggestions.

My proposal: arrows navigate history, C-n/C-p navigate suggestions. Perhaps we can be clever and say that C-n/C-p navigate history when there are no suggestions, but that might be more tricky.

[ollien]

I think that's a good default, but the surrounding UX could stand to be explored. My from-the-hip suggestion would be that going "down" go back in history if there are no suggestions, or "enter the suggestion list" if there are. If you're in the suggestion list, up goes to the previous item, or the command box if you're already at the top.

Or maybe we can 80/20 this and just put in the title of the tooltip "C-n/C-p to navigate suggestions" or some such.

[ollien]

Any reason not to merge this at this time?

[theol0403]

I haven't had time to look into this but the risk is that it currently removes the ability to select and accept suggestions using the keyboard.

[theol0403]

I'm cooking up something better 👀