jubeat: introduce new algorithm for touch (#686)

## Description of change
There was enough feedback that the current algorithm is not ideal for
most touch screens because most touch screens are not 24". In the
current algorithm touching the gap is no-op, so people think the game is
dropping touches.

This PR introduces a new algorithm that inspect touches on the gap and
triggers the nearest square.

## Testing
Tested landscape and portrait jubeat.

src/spice2x/games/jb/jb.h

@@ -4,8 +4,14 @@
 
 namespace games::jb {
 
+    enum JubeatTouchAlgorithm {
+        Legacy,
+        Improved,
+        AcAccurate
+    };
+
     // touch stuff
-    extern bool TOUCH_LEGACY_BOX;
+    extern JubeatTouchAlgorithm TOUCH_ALGORITHM;
     extern bool TOUCH_STATE[16];
     void touch_update();