Move held item scrolling into dedicated datatype

src/Dodge/Event.hs

@@ -14,6 +14,7 @@ the simulation step; in particular see 'updatePressedButtons'.
 module Dodge.Event
     ( handleEvent
     ) where
+import Dodge.HeldScroll
 import Dodge.InputFocus
 import Dodge.Combine
 import Dodge.Event.Keyboard
@@ -110,7 +111,7 @@ wheelEvent y w = case _hudElement $ _hud w of
         | rbDown -> case (yourItem w ^? _Just . itUse . heldScroll,_rbOptions w) of
             (_,EquipOptions{}) -> scrollRBOption y w
             (Nothing,_) -> closeObjScrollDir y w
-            (Just f,_)  -> w & creatures . ix 0 . crInv . ix (crSel $ you w) %~ f y (you w)
+            (Just f,_)  -> w & creatures . ix 0 . crInv . ix (crSel $ you w) %~ doHeldScroll f y (you w)
         | lbDown -> w & cameraZoom +~ y
         | invKeyDown -> changeSwapInvSel yi w
         | otherwise  -> stopSoundFrom (CrReloadSound 0) $ changeAugInvSel yi w