We are implementing that today so it will be part of a next update. The way it works is that it's attached as the same key that you use to interact with items, so if you open a chest by pressing 'e' and then you press 'e' again, you'll take all items.
Good stuff, thanks. I have the mouse sensitivity pretty low for the main game so in the menus it is quite sluggish, so this hotkey will be nice.
