Suggestion: add a "Go" menu

[warpdesign]

The go (fr: aller) menu should have the following shortcuts entries:

• backward [existing shortcut] (fr: reculer) [mod+left]
• forward [existing shortcut] (fr: avancer) [mod+right]
• enclosing folder [existing shortcut] (fr: dossier parent) [backspace]

Note: for now, do not disable item (for eg. if parent has no effect) as this means we would have to re-generate/render the menu on each directory change because of the way Electron works. So we have to be sure it's safe to run the combo in any case.