Issue #1887: Equipped items do not emit sounds

Added playing of sounds for equipped items (at this moment only for lights).

Signed-off-by: Lukasz Gromanowski <lgromanowski@gmail.com>
You can't cache the inventoryStore like this, because it would go stale when the animation's mPtr is updated (this happens when a reference moves between cells: https://github.com/OpenMW/openmw/blob/master/apps/openmw/mwrender/animation.cpp#L465).