quick menu: mouse and lightgun controls are not displayed or remappable

[markwkidd]

Description

Mouse and lightgun controls are not displayed or remappable in the Quick Menu.

Expected behavior

I expect all libretro input abstractions to be remappable in the quick menu like the RetroPad is, but this is not the case for a mouse or lightgun.

Here's what I would expect to see:

Actual behavior

Here's what happens instead:

[bslenul]

Big +1 on this, being able to save per-game/core remaps for light gun games would be a huge improvement.